Yep he's one of the people that said they used a kepspeed exhaust. I believe this is the exhaust that is on his bike. it appears to be discontinued - 9 months ago biz said it was out of stock and it still is. There is what I believe to be a successor to that exhaust system on the same site, here, but again I haven't had any luck being able to select united states as a shipping option on their website.


As much as I know it would be too loud and I wouldn't be able to use a wideband sensor, this system tingles my jingles. Oh well, I'll make the do with what I have available to me.

So basically the main issue is finding an exhaust
To clear the starter right. Sounds like it needs to be a custom job.

I have only tried the stock exhaust that came with my bike and the one I bought on ebay, there very well could be an ebay/amazon/aliexpress/you-name-it exhaust system that will work with the 190. I would go and ask the 190 swap facebook group, but I sincerely dislike facebook altogether and once they asked me to verify myself with an ID photo, I gave up on my account.

If I had the funds to test out the fitment of many different exhaust systems so you or anyone else wouldn't have to, I would. I wish I could. I am a humble being with a humble occupation, and I cannot do that. If I tally up the cost of everything I've bought on this project so far including the bike itself (granted some of it isn't needed), it comes very close to a new genuine honda grom. All I can do is tell you what to look out for, what I've learned with my exhaust, what has worked, and what hasn't.

On to slightly more upbeat news, I made a fender eliminator/tail tidy/moto-thong-be-gone! I didn't get to the hardware store today, but I did the next best thing; rummaging around all of my junk boxes, tool boxes, tool chests, spare parts boxes, scrap metal boxes, and underwear drawer for useful scraps of metal stock, bolts, nuts, shiny things, etc. I found 2x large 90 degree braces probably meant for holding up shelves, 2x small braces, hardware and mounting brackets for bicycle reflectors, lots of misc. hardware, and a one-way air valve that used to be on my scooter, and probably some other stuff I'm forgetting.

There are four screws holding the plastic cover over the metal frame inside the stock tail extension, remove those and the four bolts underneath the seat holding the tail extension frame in place and the tail extension will come right off. Be careful not to yank on the wires for the turn signals and the license plate light. The turn signals come out after you remove the nut securing them in place. The license plate light is behind about 2 or three pieces of plastic just screwed into place.

I bolted the two larger braces into the two rear former-tail-extension mounting holes. I had to drill two new 1/4" holes in the folded metal piece that holds the red reflectors. I also had to (eep) drill two new holes in my license plate so I could use the two same mounting bolts for everything. The holes in no way obscure the license numbers or the reg sticker, they are just about 3/8" inward from the "standard" holes. Where the reflectors used to be held, I drilled out the holes to a little over 3/8" and put the turn signals in there. I mounted the red reflectors on the two smaller braces, which I mounted to the bottom two holes on the license plate.

I wanted to keep the one red reflector that faced straight backward, so I bent one of the bicycle reflector mounts into an "L" shape and bolted one end to an area on the undertail plastics that looks like it was meant to hold a bolt or a screw, and attached the reflector to the other end, facing backward, a little behind the license plate.

For less than about $10 worth of scrap pieces from previous projects, I think that looks pretty good. I will eventually paint the braces black.

I got the silicone out again and REALLY sealed the MAP/IAT/TPS box, as well as went around the injector housing. I'm not sure exactly where the air leak is, but it needs to be gone. I wish I could blow some smoke through the throttle body or submerge it in water to see where the air is coming out, but I don't think that little black box would appreciate being smoked out or dunked in water. I could just take the black box off and try testing the TB without it, but that would screw up the TPS-zero and TPS-100% readings in the tuning software, as well as in the firmware on the ECU. I know how to fix and correct that, but I'm just going to leave well enough alone for now.

I connected the crankcase breather tube to the engine and added a one-way valve to the end of it so the air in the crankcase will always be at least at atmospheric pressure, if not lower, so oil won't get pushed out of any seals when there's a lot of blow-by. I routed the outlet tube from the one-way valve down toward the left side of the rear swing arm, out of the path of the rear tire. If any oil or oily-gasses escape and make it all the way out to there, they will fall onto either the ground or onto the chain. I don't think motor oil can hurt a motorcycle chain. The white spiral wire wrap is so the tubing does't kink at that tight 180 turn.

I found an old but still in very good condition small section of very large gauge wire I am going to use to ground from the engine to the frame. Right now I am relying on the mechanical connection of the engine's mounting holes and the frame's mounting tabs for an electrical connection between them. I works for now, but I don't want to rely on it long term. I'll probably bolt it up to the frame where I took a picture of it with a bolt on the engine right next to an unoccupied bolt hole in the frame, unless I can find a better place.

I also de-glazed my front brake rotor with a scotch-brite pad. I usually rely on engine braking for the first half of my braking force, and then use the front and rear brakes for whatever speed is left thereafter. So, the front and rear brakes get only light to moderate use, which ended up polishing the rotor instead of bedding the pads and rotor together. No biggie, neither the rotor or the pads are ruined if this happens, just scuff up the rotor with fine-grit (about 200 or more) sandpaper or a scotch-brite pad until the glaze is gone. You will have to press rather hard while scrubbing.

Things done: (some not talked about)

• Fender eliminator
• Zip-tie fuel pump and starter solenoid
• Reinforce battery tray plastics with zip ties
• Add reflective tape
• Seal MAP/IAT/TPS box
• Level fork height
• Add one-way valve to crankcase breather
• Forget where you put that screwdriver you just had in your hand not 3 seconds ago

Looking good. Looks like your almost done. Will then have to find a new project.

At this point I'm so bolts and nuts deep into this project, I can't see anything else when I'm falling asleep but fuel tables and wiring harnesses. I have no idea what the future will provide me as a project.

I decided to use the shifter arm that came with the 125 engine. The one that came with the 190 was poorly welded and just waiting to break off when I'm 50 miles from home or a hardware store. I may keep it with the bike as a roadside-backup, it's pretty small and lightweight, why not? The shifter that was on the 125 is also about 1 1/2" shorter than the 190's. If I have to put too much effort into the shifts because of the lower MA, I'll just buy a new one off of ebay.

I wanted to know how much all of the stuff I've taken off of the bike weighed and compare the exhaust that I'm hopefully going to be installing in its place. By my hasty calculations, everything I've taken off weighs about 15 lbs and the new exhaust weighs about 4 lbs, so a net bike weight loss of about 11 lbs! Unfortunately, thanks to a new medicine I've been prescribed, I've gained more than that over the last ~6 months. Time to go back on a diet. Maybe.

The silicone on the MAP/IAT/TPS sensor still hasn't fully cured, and probably won't for a few more days; I think I went over the maximum recommended thickness by a factor of at least 2 or 3.

The short section of heavy-gauge wire I found turned out to be too short, so I had to substitute a ground wire previously used on an amplifier. It's 12 gauge, so more than enough to return the power used by one of the relays and the ignition coil.

Not much else to say for tonight...

• mockup exhaust/confirm fitment
• replace rusty front caliper nut
• JB weld vacuum nipple on fuel pressure regulator
• new nuts for exhaust studs
• hardware for TB - intake manifold mounting
• fittings for fuel pressure gauge
• tap for vacuum port on manifold
• shaved horn button
• clip holding crank case vent hose
• re-route clutch cable

All that and more, tonight on This Old Thread!

User Whiskey has told me that he(I'm guessing, forgive me if I'm wrong) has contacted motorkit.com and they have said that they DO ship to the US. Moreover, they have the gp1 exhaust is stock and he has bought one from them. I run a number of ad-blockers and script blockers on my web browser; it is quite possible that one or more of those could have messed up the checkout page, making it appear as though they didn't ship to the US.

Meanwhile I, or rather my cat had a bit of bad luck. Nollie came in from being outside with a red front paw a couple nights ago. I'll spare the details, but she seems to be much better now. No limping, no hiding, no pain-meowls, just an occasional lick on her left front paw. I paused for about a day when that happened. Purrs > Vrooms.

On to less sad things! When Whiskey told me that the gp1 exhausts were back in stock, I was originally going to return the ebay one I have and use that to subsidize the purchase of the gp1 exhaust. However, today I finally went to the local hardware store and pickup some nuts, bolts, and washers that let me mock-up the exhaust as if there were another ~1cm of pipe added to the piece that mounts to the engine. I bought 5 washers, I forget what fractional size they are, but they're 32mm OD. I stacked those on top of the bit of exhaust pipe that actually goes into the engine and is held in place with the flange. With all 5 washers, the nuts for the exhaust studs only had about 3 threads to grab onto, but that's ok; I'm just mocking up the location of everything and I'm not going to use all 5 washers. I just bought these washers as an inexpensive place holder for these.

With the exhaust in place as it is intended to be used, the passenger footpeg and the whole "arm" that bolts the passenger peg is in the way, but the muffler is (or rather would, if the peg wasn't there) pointed out the back of the bike, not out to the side, and there is about 5mm between the exhaust manifold and the starter motor. With the exhaust installed with the mid pipe turned around, so the end that normally connects to the muffler now connects to the header pipe and vise-versa, the passenger footpeg is no longer in the way and there is still ample clearance between the starter and the exhaust manifold. Unfortunately, the spring clamps loops that hold the muffler to the mid pipe and the mid pipe to the manifold are either rotated and/or too short. So I can either install the exhaust as intended with new rearsets, or flip one bit around, keep the stock rearsets, but have to take the exhaust pipes to a welder and have them make and then weld some more spring hooks.

I'm not sure if this has come across through my posts, but I have quite severe social anxiety. Almost to the point of agoraphobia. That's why I work from home and live with family. I'm already not looking forward to taking the exhaust pipe somewhere to get the o2 sensor bung welded in, adding another thing to do doesn't sound good to me. I'll spare you the rest of the sob story, and just tell you that I'm going to be most likely buying new rearsets and installing the exhaust the "normal" way. Apologies for bringing more sadness into this post.

The hanger that come with the exhaust system is too short to hold the muffler in place. The clamp piece with the rubber in it can be mounted to the loop on the passenger's footpeg, if you choose to flip the mid pipe, but since I am getting rid of the stock rearsets, I'll have to get some metal stock and bend something that can support the muffler from one if not both exhaust hanger tabs on the right side of the bike. No biggie.

One of the nuts on the front brake caliper has started to rust, and I don't like the idea of fighting with rusted-up hardware especially on brakes, so I replaced the rusty nut with a lock nut.

I wanted to use a 90 degree hose fitting for the to-be-made vacuum port on the fuel pressure regulator, but I could only get straight ones. Oh well. I bought a 3/16 hose splicer (back to back hose barbs) and cut it in half, right down the middle. I cleaned up and scratched up the hose barb and the metal part of the pressure regulator, mixed the JB weld, and covered both side holes, and attached the hose barb to the top hole on the regulator. I tried not to use so much of that stuff that I couldn't get the cap/ring back onto the regulator. I'll have to wait 'till tomorrow to see.

In case you wanted to know, the vacuum port on these aluminum intake manifolds are threaded in, not pressed in as I thought. I was going to use the vacuum port nipple from the 125's manifold and put it in the 190, but the hardware store didn't have a (what I assume is a) 1/16 npt tap, only 1/8 and up, so I bought one of those and forgot to buy a 1/8 npt to 3/16 hose barb fitting. Oops. Next time.

I bought some new nuts for the exhaust manifold studs to replace the end-cap ones that came with the bike. I'll probably use two nuts per stud so I can make a jam nut and not have to worry (as much) about them coming loose.

I had to get a bit creative and unsymmetrical with the bolts and nuts I used to fasten the TB to the intake manifold. One side of the TB has the idle air mixture screw right behind the bolt hole, so you can't get a screw driver in there to turn a bolt, and the other side has the injector body right behind the bolt hole, with only enough to use a nut, not a bolt. So on one side of the TB, I have a standard hex-head bolt going through the TB bolt hole and threading into the intake manifold. On the other side I have a bolt with a ground-down head coming from the intake manifold through the TB bolt hole and threading into a nut that miracle-has-it just barely fits on the TB.

I had some fittings from a previous project that I can could use on this one. 4x 1/8 npt to 5/16 hose barb, 1x 1/8 npt street elbow, 1x 1/8 npt plug, 1x 1/8 npt bleed valve, 1x 1/8 npt female to female union, and 1x 1/8 npt 4-way fitting. As in the picture, I am going to have the 5/16 barbs on opposite ends of the 4-way, with the bleed valve on the top and either a plug or a street elbow + pressure gauge. I would like to be able to confirm that the fuel pump/regulator is indeed pumping and regulating and that my manifold-pressure-reference mod did something. I will be securing these hose barb fittings with clamps designed for fuel injection hose, NOT plain worm-drive clamps.

I also did a few small things. I don't know if this happens to other riders, but especially on this bike, with these controls, I am constantly accidentally tapping the horn when I move my thumb from the grip to the turn signal controls. I ground down the bit on the horn button that sticks out on the left side. Hopefully I won't unintentionally honk at so many people now. I also put a hose-retaining clip on the swing arm to hold the engine crankcase vent hose in place. However, the swing arm is going to move independently of the hose so I bent the hose clip so that the hose can still slide up and down in the clip, but not come out. Finally, I re-routed the clutch cable through a hole I drilled in the black plastic pieces on the back of the red trellis fairings. The clutch cable won't get as bent and squished between the tank fairing and the handlebars now.

I had a lot of pics to go with these topics, so I spread them out over the posts; the pictures I have posted in one post may not be written about in that particular post.

Despite knowing nothing about it, I presume that a good antidote for agoraphobia is a really good bike. That's gotta make you want to get out there.

That is very true. I'm hoping my interest in this project will overcome my anxieties and let me be more social. Adam Savage once said that he had a young fan approach him to ask a question, but he (the young fan) was unable to get the words out because he was too nervous, but his love for science and knowledge pushed him through his anxieties and let him ask his question. I'm hoping something like that happens to me.

Or, ya know... amazon delivers pretty much everything now-a-days.

I could go on and on about my problems, but that isn't what you came here for.

The only things I have to do/buy (as opposed to potential additions to the project or just nice-to-haves) before I get to wait a month or more for warmth are:

Buy:

• 5/16" ID fuel injection hose, at least 2 or 3 feet
• 5/16" ID fuel injection hose clamps
• 1/8" npt to 3/16" ID hose barb, for manifold vacuum port
• 21/64" (Q) drill bit, for 1/8" npt tap
• dielectric grease
• o2 sensor bung
• 5/16" hose barb bulkhead fitting, for fuel return into fuel tank
• fuel pressure gauge, not absolutely mandatory but I'd really like to know the pressure of the fuel being delivered to the injector
• sealing/spacing washers from mcmaster carr
• rearsets

Do:

• run fuel hoses: tank->filter, filter->pump inlet, pump return->tank, regulated pressure out->4-way fitting (pressure gauge and bleeder), 4-way fitting->injector
• drill and tap hole for manifold vacuum port, install fitting
• run vacuum line from manifold to fuel pump/pressure regulator
• dielectric grease on most connectors
• drill hole for o2 sensor bung, get said bung welded-in
• drill hole for, and install bulkhead fitting on fuel tank
• temporarily install exhaust with sealing washers
• fabricobble exhaust hanger
• sync timing between engine and ecu, might not be possible without engine running
• install rearsets
• eat
• sleep
• poop
• wait

Glavey, I'm really starting to look forward to your latest posts.

Thanks, dude! I appreciate that. I just placed an order for most of the small things I need, less the dielectric grease, rearsets, and sealing washers. I'm gonna try and force myself to purchase some items like the grease and a tap wrench locally. Hardware stores and the like are easier to me because they have much more... structured and predictable social interactions; as long as you know the technical terms for what you want to buy, things tend to go smoothly.

I'm going to have to wait, as usual, to drill/mount/install the fuel return fitting on the fuel tank until warmer weather. First, I have to drain all the old fuel out, eliminate as much of the fuel vapor in the tank as possible (drilling into metal = risk of spark, fire, explosion, and free hearing test), figure out where on the tank is a suitable location that is unobstructed by the tank fairings, as flat as possible, near the fuel pump, and if possible around or above the 3/4 full level (the fitting I am buying is sold as a "...Hose Barb Fuel Tank Fitting", but I would still feel more comfortable with my family jewels merely inches from a gas tank with a fitting that is only some of the time submerged in fuel and thus, hopefully less likely to leak and make things go boom).

I'l also have to find out how I"m going to hold the nut on the inside on the tank while tightening the fitting; the normal fuel filler hole has a metal plate underneath it with holes much too small to fit my hands through. I could always take the fuel level sensor cap off of the bottom of the tank and hope my hand or at least a wrench fits up there...

Even once I get the package, I'm pretty limited to what I can do without the fuel tank and warm weather. At most, I'll be able to run the high-pressure line from the pump/regulator to the 4-way with the bleed valve and pressure gauge to the injector, semi-finalize the exhaust location so I know where I can put the o2 sensor bung, get said bung welded in, and drill/tap/install fitting for vacuum port on intake manifold.

I tried to renew my lic plate tabs today, but I would have had to stand in line in front of the "please take a number" for half an hour before I could even sit down to wait for my number to be called. I think there was 80 or so people ahead of me. That's a big fat NOPE. You would think they wouldn't be so busy on a Tuesday during work hours.

That's about it for today.

-Just as a footnote, I too suffer from mild agoraphobia ,it's a real thing and I totally sympathise with the struggles it causes. Thats kind of the good thing about a bike, it's not the fear of outdoors for me at all, it's the "people" part of it. ,so at least I can still ride since it does not ( usually ) require much social interaction , so less anxiety for me.


That said, i have developed 2-3 good friends that don't ( usually ) stress me too much so overall my being into motorcycles has helped me a lot, i think it will help you too ,just take it slow and dont get overwhelmed by going to a major Bike gathering right off, lol!

The bike has helped me get out of the house quite a bit, even though I usually go ride around 75% of the time with no real destination, just riding around the town for an hour or so and come back.


When I do stop somewhere, even if it is just at a gas station or a barely-busy thrift store, because of my bike's unusual size and style, more often than not I get asked about it. So far all of the encounters have been positive.


Oh geez, a bike rally/group ride. That is FAR in my future if it ever even happens. I'm not this bad anymore, but I used to get a headache and have to change my shirt from sweating too much if I played a multiplayer video game.

I played around with turning over the engine with the electric starter motor while there was no spark plug, exhaust, or intake installed so I could get the maximum speed the engine could turn over. The ECU needs to know when the engine is cranking vs running, so I can set the max cranking RPM a bit above the actual engine cranking speed. Above that RPM, the ECU will assume the engine is running, stop giving the engine extra "startup" fuel, and begin after-start enrichment and warmup enrichment if needed.

I had the intake manifold and TB just hanging from some string on the bike's frame. I needed the injector and the MAP/IAT/TPS to be connected, otherwise the ECU displays a code on its equivalent of a check engine light. I connect everything up along with a 1990-ish vintage inductive timing light I bought some time back. Turn the bike on, wait for the ECU to do its priming pulse and fuel pump prime, and hit the starter button. No tach signal. Doh! I had the kill switch on. Turn the kill switch OFF, and try again. WOO HOO! It was quite nice to see that RPM gauge on my laptop move for the first time.

First thing I noticed was that the decompression valve on this engine lets the starter turn quite fast, albeit with no restriction. Second thing was sparks! The only good kind of sparks in a vehicle; from the spark plug. Big, bright, blue sparks. It appears that the ECU is "talking" to the CDI, the CDI is firing the coil, and the coil is making a spark occur at the spark plug tip, at least in open, atmospheric pressure air. Third noticed thing was my old timing light wasn't working; no flashy-flashy. I forgot to try turning around the clip-on lead, so I'm not sure if it is broken or not but no matter, I have another timing light that connects directly to the ignition coil. Fourth thing I noticed was that the tuning software recorded an ECU reset right after I let go of the starter button, not good.

A reset, in this instance, is the ECU not having enough either voltage delivered to it, or not enough current available to it, resulting in a voltage drop. I looked online and it seems like a starter solenoid isn't an uncommon thing to cause reverse voltage spikes or just bad electromagnetic interference (EMI). I can test this theory by not using the solenoid, but just bridging the two starter contacts, completing the starter motor circuit, but not energizing/de-energizing the solenoid's coil. I can also add a diode across the solenoid's coil to limit the inductive kick-back like I did with the relays. I'll test that in the coming days.

I managed to snag a datalog of the test start. The tuning software saves datalogs in a excel-style spreadsheet. You can view them in any software that can open .xls files. Viewing the files this way is quite... raw and dry. An alternative is to use the software that mega/microsquirt users use to view logs; MegaLogViewer MS. The "MS" version is the free version, that's the one I used to view the logs. It can graph any of the variables the ECU logged, and compare them in the same graph to any other variable. If you buy, I think it is the HD version of the software, you can import your tuning file from your tuning software and the log viewer will show you where in the VE table, spark table, AFR table, etc. the engine is at any specific point in the logs. I took a screenshot of the few seconds I logged while the engine was turning over.

A few more electrical gremlins tonight. First was one of the wires going into the left hand control cluster had come out of its crimped terminal in the connector. There was only about 2-3mm of insulation cut off of the end of the wire; no wonder it didn't stay in the terminal. I had to solder the wire into the terminal since it was already crimped and trying to open it would have destroyed the terminal. After a quick solder and heatshrink treatment, the wire is back in the connector and once again the passing light switch works.

Next, I did some testing and probing and disassembling to determine how the starter solenoid was wired. In case you wanted or need to know how the wires are connected in the right hand control cluster, I took a picture. Switched +12v -> starter button -> solenoid -> clutch switch -> ground. That seemed like a rather odd way to wire the clutch safety switch. I elected to remove the clutch switch all together and do: switched +12v -> starter button -> solenoid -> ground. I also added a diode across the solenoid coil's leads to limit the voltage spike from the coil de-energizing. Now, one lead of the solenoid is permanently connected to ground and the other is provided +12v from the starter button. I'll just have to be careful not to hit the starter button while the engine is already running. As for the clutch switch, I always start the engine with the clutch pulled in anyway. Worst is I try to start the bike with the transmission in gear and the starter very briefly turns then stalls, I feel the bike trying to move forward a wee bit, I let go of the starter, put the transmission in neutral and/or pull the clutch in, and try starting it again. I still have to add a diode to the main relay.

I cleaned, glued together, and reinstalled the clutch switch after I got some very high and erratic resistance readings across it. Even though I'm not going to be using it, I like to keep it in working condition in case I need it in the future. There really wasn't much in the switch, a few pieces of plastic, a spring and two terminals doubling as the switch contacts.

I am trying to have ALL grounds that can be routed or moved terminate at a single location so there is no voltage difference between the ECU ground and any of the sensors' ground. If there are too many more grounds to terminate, I may need to buy an isolated terminal to connect them all. The wire I previously installed on the left side of the bike that connected the engine to the frame didn't match my star-grounding strategy, so I moved it to where all of the other grounds were terminated, and connected the other end to the bolt that holds the rear brake fluid reservoir to the frame. You can see in one of the pics, the brake reservoir just to the right of the bolt hole that will hold it and the wire lead in place. It's getting mighty crowded on that side of the bike.

I'm going to go eat chili until either my stomach says "UNCLE!" or my bowels say "NOW!"

This is going to be a multi-post post, I have many pics to share. Pics attached to one post may not reflect what was discussed in that particular post.

I finally got a package from amazon that allowed me to move forward with a few of the remaining things left to do; FI hose, clamps, fuel pressure gauge, fuel tank return hose fitting, Q size drill bits, and o2 sensor bungs.

The vacuum port on the intake manifold was drilled, tapped, and threaded in without much fuss. The soft aluminum really made the process go faster. I chose to install the vacuum port on the opposite side of the manifold that the circular detent is on for two reasons; 1, the walls of the manifold were much thinner where the detent was and 2, the vacuum hose from the fuel pressure regulator was coming from the side of the manifold opposite the detent. Now the hose fits on there perfectly.

I drew on the exhaust where I need the o2 sensor bung welded in. Now I have to find a way to drill a 22mm hole in a pipe with a slippery chrome coating on it. The first way to do that, that comes to mind is to get a square-ish piece of wood a little larger than the diameter of the pipe and cut/gouge/sand out the shape of the exhaust pipe on one side of it, so the piece of wood can sit on the pipe and not twist around, but can still rotate around the pipe (I know, I really suck at explaining things). Then you drill a hole through the middle of the piece of wood, perpendicular to the cut out of the pipe. Now clamp the piece of wood to the pipe with the exhaust pipe in the cut out portion and the hole exactly where you want the hole in the pipe to be drilled. You now have a guide/bore for your drill bit to follow so it won't walk all over the place on the nice shiny slippery chrome.

I soldered on a diode to the main power relay. I have had a bottle of liquid electrical tape for some time, but never used it more than once or twice before. This seemed like a good time to test it out because I only stripped the insulation off of the wires on the main power relay, I didn't cut them and re-solder them back together, so I couldn't put heat shrink on the wires. I also didn't want to just wrap the diode up in the red electrical tape I've been using. I brushed on the thick, noxious smelling paste and let it sit for about 3 hours and then put another coat on. Once it dried completely, it seemed like a formidable adversary against moisture ingress, abrasion, and high voltage arcs.

I, yet again went shopping in my garage for some scraps of metal that might be able to the muffler up and away from the swing arc of the swingarm. I found a pair of angle brackets very similar to the ones I used to make a fender eliminator. I bolted one side of the piece of metal to the holes in the exhaust-side rearset, where the passenger pegs used to be, and the other side, 90 degrees bent, has the muffler support bracket bolted to it. The picture should show what I mean much better. In that picture I am using 4 of the exhaust-spacing-mock-up washers to emulate the height/depth the exhaust will go into the cylinder head. There is about 1/8" between the exhaust pipe and the starter with the exhaust system installed as it is in the picture. With the exhaust as it is now, I'll have to go out and get some exhaust spring hooks welded on at the same time I get the bung welded in. Oh well, I'll just face it. I don't think spreading a post over multiple postings is against forum rules. Mods/admins, if it is, please let me know.

I started to diagnose and troubleshoot the reset problem with the ECU and the starter. I disconnected the starter from the solenoid so that only the solenoid coil would be powered and the reset did not happen. I disconnected the fuel pump and wideband relays and the lighting circuit. The only things powered were the ECU and the main power relay. I still had the power lead from the motor to the solenoid disconnected, so I bypassed the solenoid and just touched the starter wire to the lead coming from the battery. BIG-ARSE sparks and an ECU reset. I think I'm on to something. Many more sparks and resets later, I am ~90% sure that the inductive surge from the starter when the power to it is interrupted is causing a huge voltage spike on the ground-end of the wiring on the bike. A voltage spike to ground, if received by the ECU, will almost surely cause it to reset.

Let's say the ECU needs a nominal 12 volts to operate. The voltage on the +12 wire into the ECU must be at least 12 volts higher than the voltage on the ground wire going into the ECU. The ground wire could have 1000 volts (referenced to earth) on it and if you connect 1012 volts to the +12v wire, the ECU will operate as it should, provided there is no reference to earth ground anywhere on the ECU. If the ECU's ground voltage is pulled up too high from things like stray inductance, a magnetic field collapsing, rapid high power switching, etc, then there won't be enough voltage difference the +12v and the ground at the ECU to let it keep functioning properly and it crashes and resets.

So I need to suppress that inductive spike. This is a bit beyond my knowledge set, since I can't really "intercept" the ground signal like I can on a relay; the starter motor is more-or-less permanently attached and grounded to the engine, so I can't exactly put a diode in-between the motor and the engine. I started a thread on the arduino forum asking for assistance with suppressing the inductive "kick" from the motor. I already have a few things I can try.

That thread on the arduino forum also made me realize that I think the wiring on this from-china ECU is probably its weakest link. ALL the wires are too small gauge to carry enough current and not have dramatic voltage drop and too short to isolate electronically noise components, power hungry components, and sensitive analog components from each other. You can see how small the ground wire is in the picture.

For this EFI kit to work WELL and RELAIBLY, I will most likely have to crack open the case and hopefully be able to solder on some thicker gauge wires, proper grounding wires, and sensitive analog signals shielded all the way to the ECU box (notice I said work well and reliably, not just work. I am sure that this kit will start and run and engine, but it will at some point probably have an electrical gremlin or two that will be very difficult if not impossible to squash without opening the ECU.)

I am going to try to keep the wiring coming from the ECU as close to "stock" as I can so I can test the kit as anyone else who purchased it would have it wired. If it turns out that I cannot reliably control the engine with the stock wiring, I will dive right in to the ECU case and crack it open like a walnut. I don't want to open the ECU just yet, I haven't even tried to start the engine with it yet and I don't want to condemn the ECU because I just thought I would have a problem with it.

The fuel tank fitting, of course, requires drilling a hole in the gas tank. Drilling a hole in metal causes heat, hot sharp shrapnel, and possibly sparks. Gas tanks have... gas in them. Gas + oxygen + spark = the kind of boom you want INSIDE your engine, not outside. I drained out all of the gas from the tank and took off the filler cap. Now I'm just letting the remaining gas and gas fumes evaporate and leave the tank. With the temperature so low, that may take a while. I'm going to have to get all of the vapor out of the tank because I realized that I really do need the tank on the bike to know where I can route the fuel hoses and where to put the pressure gauge so it can be viewed with all of the fairings on. So I can't run the hoses, install the return fitting, or position the pressure gauge before I get the tank nice and empty.

I was able to sync the timing between the engine and the ECU despite the reset issue. One thing that made it much easier was a printed pulley/crank/flywheel degree ruler. This site lets you enter the circumference of the wheel you want to degree and gives you a printable degree ruler you can tape/glue to whatever you need. I temporarily stuck it to the magneto so I could see the degree markings through the peep hole on the engine. Of course, I could only do this at cranking speed, not idle. I had to remove the intake manifold and keep the spark plug out so the engine could turn as fast as possible. With the spark plug in, the timing jumped between 10 and 20 degrees BTDC because on one rotation of the crank, the motor had to compress a cylinders worth of air, slowing it down a lot, and on the next rotation of the crank, the exhaust was being pushed out, so very little slow down there.

• o2 sensor and exhaust spring hooks welded in
• install return hose fitting in tank
• plumb fuel hoses
• solve or minimize reset issue
• permanently mount exhaust
• wait

That's it. The last 10% is the longest 10%.

Two steps forward, one (big) step back; that's the current situation with the ECU resetting itself.

To eliminate the possibility that the USB cable was somehow receiving interference from something electrical on the bike, causing the software to detect a reset, I made a bluetooth adapter to use in its place. I had a spare serial-to-bluetooth adapter from a previous upgrade on a 3d printer and a very common chinese buck converter (feed in any voltage up to the chip's limit, it will output a stable, selectable voltage. I just had to buzz out which wires were transmit, receive, power, and ground. Luckily the aliexpress ECU outputs serial data at 3.3 volts, the same voltage that the bluetooth adapter uses so I didn't need to use a voltage-level shifter. Now I just need to package it up, neat-and-tidy in some small box or something... I'll find something.

The adapter works with my laptop's internal BT communicating with the tuning software, on two of my cellphones, but not on a usb-bluetooth dongle I use for my main PC. Oh well, I intend to do the majority of tuning on my laptop. However, even with the wireless connection to the ECU, the resets were still happening...

My initial assumption that the ECU reset was caused by the starter motor were wrong. I discovered that if I turn the engine over using any method (e-starter, kickstart, socket/ratchet on the crank bolt) while the kill switch is in the RUN position, the ECU resets itself. When the kill switch is in the STOP position, it grounds the signal coming from the trigger coil; when it is in the RUN position, it has no effect on the trigger coil. So, it is the trigger coil itself that is causing the resets.

My first thought was that one of the two wires coming from the trigger coil is grounded, when usually in EFI systems both wires go back to the ECU. The manual for the microsquirt states: "...The Microsquirt measures the voltage from the sensor and converts it into a temperature, position etc. reading. If that sensor is grounded to anything other than the Microsquirt itself, then that input voltage will be altered by any external voltage drops. ...Tach input (e.g. crank, cam sensors) will be even worse - they can show false or missed teeth and cause syncloss due to the ground voltage difference..." The aliexpress ECU does not have a ground wire for the trigger coil to attach to. Without an rpm signal, an ECU is worse than a paperweight. I decided in order to give the aliexpress ECU the best shot at working, I had to crack open the case and solder a new wire to a good ground point. Opening the case was quite easy. 6 small screws and some lightly adhesive conformal coating was all that held it together. My first reaction was... Dang, these motoEFI guys (the tuning software and the ECU firmware are both have their names in them) even had a custom PCB created. I absolutely thought that the board inside the case was going to be a clone of one of this or this. Nope, looks like they (motoefi) have put on the PCB only what is needed to run a one cylinder engine on a particular configuration without many of the extra features like knock sensors, vehicle speed input, flex fuel, etc. Also, the I'm guessing... mosfets? they are using to switch the injector and the fuel pump aren't connected to any heatsink. One of them has a very small piece of metal adhered to it as an added thermal mass and the other one had nothing on it at all. The soldering is IMHO, just passable - the solder joints look very dry (lack of flux), maybe even hand-soldered. The main IC had its name scratched off, as did one of the suspected mosfets.

After having taken a good look at the ECU PCB, considering options, trying to filter/condition/shield the signal from the trigger coil, and many other things, I have decided to stop using the aliexpress ECU if I cannot get this issue solved with minimal extra cost or effort. I still have a few ideas in my head that I think might do something, but if the problem is what I think it is, I and possibly other people who buy this kit will have to buy a $25-$70 circuit board that will condition the trigger coil signal and/or a oscilloscope to see what output the trigger coil is giving in their particular case and filter it as needed. Either way you are spending time or money or even both. Sorry dudes, but at least in my case it looks like the ECU from aliexpress won't work without monetary or time investment that is equal to buying a real/genuine/brand-name ECU. I hate to stop using the ECU before I even get to try and start the engine, but as I said above, without an RPM signal, an ECU is worse than a paperweight. The other hardware and sensors from the seller seem to be working fine. This kit may still be a viable option if you just need everything except the ECU, as I did. I had a heck of a time searching the internet for a small-engine-sized throttle body. There were only a few sellers and most of them had odd/different mounting points where the TB bolts to the intake manifold. Ecotrons is an option, but their small engine EFI kit is $600, the tuning software is, in my experience, difficult and unintuitive to use, and I doubt you could purchase all the supporting hardware minus the ECU for less than the aliexpress kit.

After I try all that I can to get the aliexpress ECU to accept a trigger coil input and mapped out which wire goes to what thing, I'm going to need to re-run and maybe re-wire most of the EFI harness. At the time I wires the bike, there were no thoughts given to keep high power wires and sources of noise isolated and apart from low power signal wires, the wires from the ECU were to short to have anything but a rats nest. I'll also have to try and keep electrically noisy parts like the regulator/rectifier, wideband controller, ignition coil & lead, fuel pump, CDI, and relays to one end/side of the bike and the sensitive stuff on the opposite side/end. I'll also need to get proper water-resistant connectors and wire whose gauge size is suitable for how much current it will carry. And a crimp tool. And wire shielding sleeves. And heat shrink tubing. And a "real" fuse/relay box. And blackjack. And hookers. Time to save up...

So much for that teeny tiny little left to do/buy list.

I'm actually starting to wonder if I will get this done before warmer weather starts to appear...

Seeing the internals of the microsquirt as compared to the aliexpress ECU gives me much more confidence about switching to it. The build and soldering quality are much better and most importantly to me, it has a hardware filtering circuit for the trigger coil built-in. The wiring loom also has much longer, higher quality, labeled wires.

The only place that wasn't electrically noisy and had enough space to hold the ECU was where I had installed the fuse box originally. I moved the fuse box to right in the 90 degree corner of the frame, where the front-half meets the back-half, right below where I mounted the relays. The ECU didn't completely fit without modification - I had to cut off the four mounting tabs on the case and secure it with zip-ties. I swear zip-ties have helped me more in the last few months than duct tape has throughout my whole life. There really isn't much space between the bottom of the seat cushion and the top of the frame bars where I mounted the ECU. I had to butt the ECU right up against the little pillar the holds the screw for the battery hold-down, I had to cut off the little plastic pieces that on the real grom hold spare fuses.

I'm going to try my best to separate the power wires from the signal wires; I'm going to run wires for the lighting, fuel pump, R/R, ignition coil, wideband controller, and injector on the right side of the bike, and keep all of the lower voltage sensitive signal wires on the left side. I'm going to have to find a way to move the R/R to the right side of the bike, as it is now it's right where the sensor harness will be.

I had previously purchased an automotive ignition coil, GM "truck" coil (acdelco part# d585, gm part#10457730) to use when I installed the microsquirt. Well, the time is upon us and it was installed. The old ignition coil was RIGHT next to the TB and probably would have caused interference. I installed the gm coil on the right side of the bike, using the nuts on the frame that originally held up the air filter. The coil hasn't really moves that much farther away from the TB, but the whole bike's frame will be in-between the coil and the TB and sensor harness.

I took the wiring harness that came with the bike and un-did all of the electrical tape and soldered all of the points where they used a crimp to join wires. If done properly, crimping wire ends together works very well and will be very reliable. However, this is a Chinese bike, and we all know that the wiring on these bikes is sub-standard. I didn't bother to remove the crimps, I just flowed solder over all of the wires and the crimp together. Taking the wiring harness to pieces also lead me to find out that the connector that plugs into the 125 engines and tells the dashboard what gear you are in is, except for the neutral wire, is just one miniature wiring harness. The wires go from the connector on the 125 engine, to one of the dashboard connectors, to the dashboard. So, if anyone swaps in an engine without a gear indicator and doesn't want that connector just flapping in the breeze, you can take the harness apart and remove the mini-harness completely and tuck the wires from the dash behind the headlights.

The next amazon order will be things for the wiring harness; insulated battery post, heat shrink, waterproof connectors, crimp tool for said connectors, and braided metal sleeving.

Interesting choice on the GM coil. What prompted that?

As much as I would like to be as frugal as possible during this project, re-using the CDI and coil from the aliexpress kit seemed to be a bad decision. As I said in one of my previous posts, I wanted to give this EFI conversion every chance at success. One of my character flaws is that I get discouraged very easily. Anytime (example: now, with the wiring harness) I have to go over something I've already done and put much effort into, I get the mental thought of,


"Oh come on! I just got everything together and I was 10 minutes from starting you up, and now I have to tear you back down again and re-do what I've already done."


I can foresee possible problems with the aliexpress CDI, causing me to have to tear down the wiring harness for a third time; using a possibly never-used-before-with-a-microsquirt ignition system, only having presumably one person a continent away for support with a small bit of a language barrier (he/she responds in english, but it can be a bit broken, but understandable at times), having the same person be the only source for a replacement, the CDI and coil are separate and larger in comparison to the gm coil, seeing the soldering quality in the ECU, the CDI is suspect, you get the idea.


If I use the GM coil; it is widely used with the microsquirt, probably available at a local auto parts store, has lots of technical community support, the microsquirt's hardware manual lists it as a possible ignition system option and gives the pinout for the connector, the coil ignitor and ignition coil are together in one small package.


TL;DR I think that the GM coil is the best bet for a reliable, replaceable, and easily diagnosed ignition system.

Update time!

Packages have arrived, items have been installed, tools used, blood sacrifices made multiple times, and sensors "talked" to the microsquirt. Ok, I'll see you in the next post.

Just kidding

The package from mcmaster carr came first; the aluminum sealing washers for the exhaust and a 12" length of 3/16" dia. stainless steel rod, for making the exhaust spring hooks. The exhaust washers (sounds kinda weird doesn't it? like a muffler bearing or headlight fluid) fit perfectly and I can't see how they could introduce any measurable restriction to exhaust flow. I'll be using 5 of them to get the spacing between the exhaust and the starter where I want it to be. I bought the same diameter stainless steel rod that was already welded on to the exhaust system. I figured I'd just stick with what size they use since it seems like it will be bendable with a bench vise and a hammer.

I also started (haven't completed) drilling the hole in the exhaust for the o2 sensor bung. I had my doubts about the exhaust system really being stainless steel until I started to try to drill into it. I think I snapped one drill bit and dulled at least 2 more. The largest HSS twist drill bit I have is 1/2', so I incrementally drilled through the exhaust with each ascending drill bit size. I had some metal rotary rasps that I was going to use to enlarge the hole to 7/8, but they dulled almost instantly. It seems the internet's general consensus on drilling sheet stainless steel is a stepped drill bit, so that's what I ordered. The bit arrived today and I'll drill out the hole in the coming days with the bung and hook installation coming probably a week or 2 after that.

Next was the package from amazon; tinned copper wire shielding sleeve, scope probes, scope probe adapters, manual vacuum pump, terminal crimp tool, 2-way connectors, 4-way connectors, 5x 10k NTC thermistors, strain gauge drivers/interface circuits, handheld oscilloscope, rs232 to TTL adapter, 50x strain gauges, and injector connectors and terminals. Yep, 90% wiring stuff. You already know what I have to do next...

The copper wire sleeving is for shielding the sensor wires going into the ECU. The scope, scope probes, and probe adapters are for diagnosing electrical issues. As you can see, I am expecting at least SOME electrical issues. The manual vacuum pump is to enlarge my di-... uh... calibrate the MAP sensor to the blank tune on the ECU and to test if the vacuum-referenced mod I did on the fuel pump is working. The connectors and crimp tool are for neatening-up and weather-resisting the wiring harness. The thermistors were a bit of a last-minute addition - I have a few temperatures like oil temp and CHT I'd like to log and adding them to the bike should be easy, plus I"m always playing around with arduinos and having more temperature sensors is never a bad thing. The strain gauges and the strain gauge drivers are for an attempt at making a quick-shifter switch by measuring the strain of either the shifter arm or the shifter rod. If all goes to plan (it won't) I should be able to measure the force my foot is exerting on the shifter and at a given amount of strain, send a signal to the ECU to cut the ignition for a fraction of a second so the tranny can unload and shift into the next gear. The rs232 (serial port connector) to TTL (microcontroller-friendly voltage levels) adapter is for adding bluetooth to the ECU. The bluetooth dongle I have requires 5v MAX transmit and receive voltages, I think rs232 uses up to 24 volts (+12v for positive signal, -12v for negative signal). The adapter will allow me to pass the serial data coming from the ECU to a bluetooth dongle and allow my laptop, smartphone, or almost any other bluetooth enabled device to log data from it.

The main Idea I had for the wiring harness, connectors, electric component placement, and general layout of the bike was front-to-back; more electrically noisy devices like the ignition coil, wideband controller, and the regulator/rectifier, power hungry devices like the fuel pump, and then the ECU under the seat. On the left side of the bike is the sensor/sensitive electronics and wiring side; most of the sensors are on the left side of the bike and it is always a good idea to keep electrically noisy and power-hungry devices away from sensors that use low-voltage, low-current wires to send their signal to the ECU. The right side of the bike is the power side, with the starter motor, starter solenoid, fuel pump, and ignition coil. I realize that there is only a small piece of metal between all of the sensors and the noisy/hungry devices, but given the size of this bike there isn't much more I could do.

There isn't much to be said about putting the 2 and 4 way connectors on. I noted where each wire went and what it did while still using the normal connectors, cut the normal connector off, (where necessary, almost everywhere) trimmed one or both ends of the wires to be connected so there wouldn't be connectors everywhere with 12" tails on them, crimped the new terminals on, and installed the terminals in the connectors.

In one of the pictures, you can see a detail shot on a star-ground point I made and am using. Everything minus the stator and the ECU sensors ground to that point. Hopefully this will eliminate or at least reduce voltage differentials between the ECU and anything else.

The wires that came soldered to the crank position coil (VR sensor) weren't shielded in any way. I wanted to make sure that those wires were shielded as much as possible from the sensor to the ECU. The copper sleeving wouldn't stretch enough to fit the connectors in, so I had to leave that part unshielded. I removed the factory wires from the VR sensor and soldered in the shielded wires that came with the microsquirt ECU, you can see a shot of the VR sensor in the pics.

The kill switch, as it was, would kill the engine by grounding out one of the leads coming from the VR sensor. This isn't really the "correct" way to stop and engine while keeping the ECU on. The more common method is to disconnect power from the ignition coil. To disconnect power from the ignition coil, I would need the kill switch to be normally closed (when in the run position, the wires coming from the kill switch will be connected; when in the stop position, the wires will be disconnected), but since the bike originally stopped the engine by switching a wire to ground, that means that the kill switch was normally open (run position = wires not connected, stop position = connected). I was very fortunate and happy after I opened up the right control cluster to see that there were 3 points for wires to connect to on the kill switch. One was common, one was normally open, and one was normally closed. From the factory the wires were connected to the normally open and the common points. I just switch one wire from normally open to normally closed. Now I have a kill switch that will stop the engine and keep the ECU on.

In the last pic you can see some of the progress, from top to bottom, of the wiring harness being made.

Smallish update today.

Since I had already wired up the bluetooth module I have for the aliexpress ECU, and I'm now using the microsquirt, I had to undo part of the wiring I had done. The connector that the aliexpress ECU used for tx/rx data had four wires going into it; switched +12v, tx, rx, ground. The microsquirt only has tx, rx, and ground so I had to source switched power from somewhere else. I decided to tap into the switched power wire that controls the lighting and dashboard. I ran the wire from where I tapped into the wiring harness along with a ground wire to just behind the ECU under the seat with some leftover length just in case. Now, I didn't want to just bundle up the bluetooth module, the voltage regulator, and the rs232-ttl adapter in a ball of electrical tape; I have been trying throughout this project to do things better than I would normally, and try and make things look... better. Not good, just not a, well, a ball of electrical tape. It turns out that the case that the aliexpress ECU came in would perfectly house all 3 modules and still be able to close. One of the pics shows how I laid out the modules and another shows the case back together with hot glue doing its best to seal it.

It turns out that the spot that I wanted to mount the, lets call it a BT case, right behind the ECU wouldn't work, the seat would come down and press on it. I decided to mount it to the inside of what I am calling the bike's left side quarter panel. It's the black plastic fairing piece with a wire mesh "vent hole" that's above the rearsets. The wires for the power would still reach, thanks to the little bit of extra length I gave myself. Thanks, past self! The serial cable for the ECU is probably 4 or 6 feet long; more than enough to mount the BT case anywhere on the bike. I opted for the good ol' faithful zip ties to mount the case to the fairing.

One of the things I had to redo since I switched ECUs is re-sync the ECU timing to the engine's timing; essentially making sure that the engine is at a given timing degree when the ECU thinks it is. I had trouble getting my timing light to flash on every spark. When the engine was turning over at a constant speed, the timing light would only flash about once every 2-5 sparks. I took the spark plug out and grounded it against the engine case and tried cranking the engine again. I noticed the first 2-3 sparks right after starting to turn the engine over were big, bright, blue-purple sparks and then only once every about every 5 sparks. Between the big sparks were tiny little pissant sparks that I'm guessing weren't enough to trigger the timing light to flash. I am still using the battery that came with the bike from china, and all the attempts at turning the engine over to get the timing correct had dragged the voltage down to near 11.9v (charged 12v lead acid batteries are usually ~12.6v) . Time to put the battery on the charger and go solve another issue somewhere. A few hours later, with the battery at ~13 volts, fresh off the charger, I tested the timing light and the whole ignition system using the tuning software's ignition/injector test mode to eliminate any cranking-related problems. This mode lets me fire the spark plug with a given dwell time, at a given RPM-emulating speed manually. It appears that the low battery was at least contributing to the weak spark, because I got every time big, bright, audible sparks.

I hooked up the timing light to test it again, but the usual mild hum that normally comes from it when the trigger is pulled was absent. Jiggling the power leads didn't help any, so I cracked it open and spotted what looked like a place where two insulated wires were touching and had probably shorted together. I replaced one of them, the other seemed good enough to continue to use. That fixed it right up. Bright flashes from the spark plug and the timing light! The blueish-purple wire in the pic was the one that I put in as a replacement.

One thing that had come to my attention when I was re-soldering the kill switch is that since I had to re-wire the kill switch, the tachometer in the dashboard would no longer receive a signal because the kill switch and the tach used the output of the non-grounded wire from the trigger coil. The trigger coil/VR sensor is now directly wired to the ECU and I'm not going to compromise the integrity of the signal by splitting it to other devices. Luckily the microsquirt has an output just for such an occasion. I can designate one of four spare outputs to give a dashboard-friendly tach signal. It would have been rather odd to just take pics of the dashboard with various RPMs displayed on it, so I shot a video showing a few different test frequencies sent to the dashboard.
shot a video

One of the other outputs I am going to use as a warning light for either the cylinder head temp, overall cylinder temp (where the engine temperature sensor is bolted to the engine in my previous posts), or oil temp. Another I might use as a warm-up indicator - if the ECU is feeding the engine extra fuel because the engine is still not up to operating temperature, this light will be on. The possibilities for setting(s) what will cause an output to turn on/off and under what condition(s) are nearly limitless.

That's about it for now. In the coming few days, I will try and take the exhaust to get drilled (the step bit I bought didn't work out) and welded. I cut the SS rod I bought from mcmaster carr into short pieces and bent them into hook shapes with a bench vise and a hammer. If the shop I go to isn't able to drill out the hole in the exhaust to the size I need, there's no way around it, I'll need to buy a drill press and a GOOD ($50+) cobalt-containing drill bit, be it twist, step or otherwise.

The unusual sparking issue has persisted so I went and asked on the megasquirt forum what could be causing it and/or if I didn't have the settings right in the tuning program. Turns out in the case of the zs190 engine, the ECU needs to think that it is controlling a parallel twin engine. The ECU, as it is configured, thinks the signal from the crank VR sensor is coming from the cam/distributor (spinning half the speed of the crank), so it thinks the engine is spinning twice as fast as it really is. The ECU needs an RPM input signal once per 720 degrees (4 up/down strokes) on a single cylinder engine. I can tell the ECU that the engine is a parallel twin (which would need a RPM input signal once every 360 degrees, which is what the 190 does) and just ignore the spark output for the second cylinder; that way I'll be running wasted spark on just one cylinder. It does seem like a bit of a work-around, but my particular use case is probably very rare for these ECUs, they are mostly for 4+ cylinder engines. I have yet to test and confirm what I've been told to do on the megasquirt forum, but I'm positive they won't mislead me.

I noticed from the first day I had this bike that on the LCD dashboard there was a section that was there, but not being used with the abbreviation "TEMP". It's to the right of the word "total" and above the odometer numbers. Curiosity got the better of me and I took the dash off the bike and took it apart as much as I could. luckily there was some silk-screen labeling next to the main connector that seemed to match what wires went to those connectors. I didn't write down all of the wire <-> PCB connections, most of the important ones are clear like power, ground, ignition, neutral, right turn, left turn, high-beam. There were also 6 pins, all together in a line, labeled oddly enough 1-6. Thats where the stock engine's gear indicators went. But... there's 6! Assuming you have an engine up to 6 speeds that has gear indicator outputs for each gear, this dash will display your current gear. Of course, this does me no good, all I have is a neutral indicator. Oh well.

I tried probing around the two unused connector pins, but got no reaction from the dash. I did, however, discover two more... enticing things about this dash. First, above and to the right of the neutral light and above and to the left of the high-beam light, there are two more indicator light "channels" WITH an LED for both of them already soldered on the PCB! There are also icons (a thermometer for temperature and a generic check-engine-light) already engraved in the black plastic piece that covers the dash. So, theoretically, even though I haven't been able to get one of those LEDs to light by probing the main connector, I could just drive one of those LEDs with an output from the microsquirt directly (with a resistor). One problem with that is that I would have do de-solder all of the LCD connector pins to be able to get to the side of the PCB where the LEDs are mounted. I don't think I can do that.

The second thing I discovered is how to change some parameters on the dashboard. I don't know what the parameters are for and I don't know what I would be changing them to, but I can (won't though) change them. With your bike off, press and hold the "CLR" button while turning on the ignition. Something like what I have taken a pic of should be displayed. I THINK that one of these numbers is a calibration for the speedo. I'm not positive what the other number(s) are. I'll look into it.

A few more parts and services; non-chinese fuel lines all-around, tap and die for the most common bolt thread pattern on Chinese scooters/bikes - M6x1, and I finally got the exhaust bung and hooks welded on. It could look better, but it appears to be air-tight and that is what matters. I had them drill out the hole for the bung, that saved me from having to buy a drill press and a very expensive bit.

Ironically, I also bought a drill press. I decided that paying the price of a drill press to not have to hurt myself trying to hold a drill straight AND press it into the work was worthwhile.

I know I've said this before and I'm gonna jinx myself even thinking this, but there is very little left to do;

• Ignition gremlin squashed
• new sensors installed and connected (I'm most likely going to swap the coolant, air intake, and map sensor with genuine GM parts, for piece of mind)
• wiring harness finished
• fuel lines plumbed
• final exhaust installation
• wait for warmer weather

:tup: Excellent documentation of the process. I've read through this thread a few times.

interesting dash... looks like a clone of the Trailtech Vapor with their snap on "dash" for indicator lights...
'
https://www.trailtech.net/media/cata...or_022-pda.png

Thanks, dude. I'm just trying to give as much info as I can in the hopes it helps someone else.

That could very well be true. It is also strikingly similar to a genuine grom dash.

While were talkling about dashboards, I found out what all or at least most of the pins on the main dashboard connector do. I take no credit for discovering this information, I just found what others have posted on the internet.

From what appears to be a Japanese person's project blog, I found this picture:

http://www.rvf-rc45.net/wordpress/wp...182_Manual.png

showing the pinouts from a similar universal type dashboard and most of the silk screen labels match. I also discovered another kind soul that took pictures of the instruction manual that comes with the grom-style dashboards. On this product page a reviewer posted the manual that is shipped with a universal dash. It describes how to get into the settings menu (the same as what I described in my previous post) and more crucially, what those numbers mean. I couldn't figure out how to directly download the images posted from the reviewer, so I took screen shots and I'll attack them to this post. Again, I take no credit for taking these pictures, I am just re-posting them here in case that amazon product page goes 404. The images are very small and grainy, so I'll try and transcribe the important bits.

The first set of three numbers in the configuration menu (after you press and hold the CLR button and power on the ignition) is the circumference of the front wheel divided by the number of magnets used for the vehicle speed hall effect sensor. I REALLY don't know how I was getting a nearly correct speed reading with that set at 021. Someone else who reviewed the dash said,

"...I have a 21in front wheel, started with a setting of 005 and worked up to 008 and that setting seems to be the closest to the GPS speed..."

So perhaps some trial an error is needed to get a good, accurate speed reading.

The second set of two numbers is setting the resistance for the "oil level" (I think they mean fuel level) and the number of ignition events/engine cycle. The first number is the resistance for the fuel level sensor. The manual says 1 represents 100R (100 ohms) and 5 represents 500R (500 ohms). I just measured the resistance of the fuel level sensor in my tank and when empty, it reads 100 ohms +/- 2 ohms; full it reads 10 ohms +/- 2 ohms. That matches the number "1" in the pic I took of my dashboard settings. The second number is the tachometer setting. "2" is for single cylinder engines and "4" is for 2 or 4 cylinder engines. Again, this matches what was shown on my dash.

It appears that this dash is quite suitable for a range of bikes. I suppose that isn't very surprising considering Chinese manufacturers are very good at re-using existing parts in new designs.

Phenomenal thread. I wish the 190 engine had been available when I still had the Honda S90.
I would definitely stick with a good old carb.

This thread is now a sticky. :tup: To much info here to get buried in the forum.

When I first read about the existence of the 190, EFI wasn't even on my mind. I think all the reading up on people doing swaps with them triggered something in my mind to think about all of the engine-related projects I haven't yet had the chance to do. I think I came across a youtube video of someone with an FI 190. That put EFI in my head. I remembered back a few... wow, more than a few, maybe 10 or 11 years ago I was reading a book about either turbocharging or EFI tuning (neither of which I could even dream of doing at that time, but I was and still am information hungry) and the author mentioned megasquirt. That put megasquirt in my head. Then I read a post on a forum, it may have even been this forum, that there was a seller on aliexpress offering small-engine EFI kits inexpensively. That put the aliexpress kit in my head.

After that, my future project was set in stone.


Ah shucks, my first stickied thread. All of you are going to make me blush :hehe:. In all seriousness, thanks dude, I really appreciate that.

I got to trying the new 2-cylinder settings today. There are a few combinations of settings in the ECU that could give me the amount of fuel and number of sparks I need. For now I'm settling on "2" cylinders, one injector, wasted spark, one injection per engine cycle, engine and injector size stay the same. From my understanding, these settings will tell the ECU that there is a single injector shared between two cylinders in a parallel-twin configuration. Spark is shared between the "two" cylinders; when one cylinder is on it's compression stroke, the other would be on it's exhaust stroke, so the spark can happen on both cylinders at the same time. We only have one "real" cylinder, but the spark output from the ECU will still work.

In the real world, on the bike, the electrical gremlin was still there with the new settings. I had also noticed that the tachometer signal was wildly jumping around. There was a setting in the ECU to filter out rogue crank speed signals. I can choose one or a combination of noise rejection settings based on the width of the tach pulse, dead time after tach pulse received, and time between pulses. I started with using the width-based rejection and after a bit of tuning, I have it almost acceptable. Within a few days, I'll try using the time-between-pulses (they call it tach period rejection) setting with and without the width-based filter.

I have been giving thought to staring out with going fuel-only ECU control during the first part of the tuning adventure. Unless I had a really lean mixture, I have never had a scooter/motorcycle CDI cause knock. The spark advance map I have now is a copy of what was sent on the aliexpress ECU. I have no idea if it is good, let alone safe. If I use the CDI and CDI coil, I only have to worry about a lean mixture blowing up my engine, not over-zealous ignition advance. Luckily I had the foreskin... I mean forethought to keep the crank VR sensor usable by a CDI and kept the stock CDI connector wired into the harness as well as the CDI coil's power feed and ground wires. I haven't yet made the final decision to use the CDI or not, but as long as I can send the crank VR sensor's signal to BOTH the CDI and the ECU with little to no signal degradation, I will be leaning toward the CDI.

Back to the dashboard. I used the pinout diagram I showed previously and mapped functions to all of the pins on the dash's main connector. The only differences in the PCB labeling was; the +5v to the front wheel speed sensor is marked "H+" on the dash, not "5V", the check-engine-light was labeled "F", not "DP", the fuel level input was labeled "EF", not "FUEL", and the tach signal was labeled "ZS", not "REV". Nearly all of the wire colors are different along with the pin positions in the connector, but ALL of the connections were there!

The main connector the dash uses is almost universally used as a power connector for motherboards. Google "ATX 20 pin connector" and you'll see billions of results. I happen to be a hoarder of extra/surplus wire, as well as all things electro-mechanical. I had on old power cable from a modular power supply. I extracted two wires with terminals from the cable and plugged the terminals into the two vacant spaces in the dash's connector. Now I had easy access to those inputs while the dash could be fully connected to the bike. I love when stuff like that just falls into place.

On one of the pictures I posted before from an amazon reviewer had resistance vs degrees points for the temperature input pin. It looked like the resistance went from about 80 ohms (120 degrees C), up to about 500 ohms (60 degrees C). I got a 1000 ohm potentiometer and connected it between the dash's temp input and ground. I didn't hook up a multimeter to see what was happening at what resistance, sorry. If I turned the pot all the way to one side (less resistance), the temperature indicator eventually turned on. If I turned the pot all the way to the other side, eventually the indicator light would go out. If I turned the pot to the middle, and then clicked through the display modes on the dash (odometer/trip), a temperature would display on the dash! To avoid confusion and increase compatibility, the dash will just not give you the option to view the temperature if it thinks that either nothing is connected to the temp input, but it will turn on/off the temp indicator without the temp display if you connect the temp input straight to ground. I heavily suspect there is some hardware or software smoothing of the temperature signal. I measured a 14 second delay between grounding the temp input and the indicator light coming on, and a 8 second delay when letting the temp input float (not connected to anything). Not exactly a basic on/off light, bit still perfectly usable as a indicator. Also, the temperature display on the dash goes from 0 degrees C to 71 degrees C. At >= 46 degrees C, the displayed temp starts to flash, and the indicator light turns on steady. At 71 degrees C, the temperature stopped rising as I was still turning the pot, and eventually the temp display went an odometer, but the temp indicator light stayed on.

The input for the CEL is just a basic light connection. Just ground the CEL wire from the dash and the indicator turns on instantly and turns off instantly when left floating. Both the temp and CEL light are red, though the CEL looks orange in the pics.

With the dash on the bike and connected to the wiring harness, all the indicator lights still worked and the temp display could be summoned if needed. Looks like we have two more free indicator lights. Almost.

The clear acrylic that covers the dash has a black plastic backing piece glued to it that is blocking us from seeing the two "new" lights. I don't think I could drill precisely enough to only go though the black plastic and not the clear. Unless I think of a better way, the current kinda-planish-thing is to just drill straight through the back and clear plastic, get some CLEAR silicone/silicone alternative/epoxy/glue/resin, and fill the new light's holes up to the thickness of the arcylic piece (guesstimate ~ 1.5mm). Although I don't intend to ride in rainy weather or to store this bike out of a garage, keeping the dash as water/weather resistant as possible is something I want to do.

I think that is it for tonight.

Your factory dash looks a bit different than mine. I think the Ice Bear Fuerza has a dash that is closer to the Grom's.

Here's the wiring for mine. Not sure if this helps or would be useful info for you.

http://www.chinariders.net/showthread.php?t=21374

I'd like to swap to that Trailtech. Looks really nice. :D

Yeah, it looks like the icebear's dash is more of a copy of the grom's dash, whereas mine is I guess "inspired" by the grom.

From a cursory glance at the colors and pinout, it appears that both of our dashboards are compatible with each other; they use the same color wires for functions and might even have the same LCD, just in a different case.

Even though I don't immediately need the information you posted, I am always ravenously eager to learn and discover new information.

I might be a computer.

I just got done painting the small metal pieces for the license plate holder and the muffler support as well as making the two hidden indicator lights in the dash visible while riding. It isn't pretty, but it works. I'll do a full-length post within the next few days showing what I did.

Yesterday the high temperature outside was around 66. Darn you mother nature, taunt me no longer!

Taking a break from stuff like a rats nest of a wiring harness and settings like crank trigger offset angle to doing something comparatively mindless like painting is a welcome reprieve. I took all of the angle brackets I used for the license plate holder and the exhaust hanger bracket outside (it happened to be a warmer-than-average day), ground them down to bare metal and primed, sealed, painted, and attempted to clear-coat. All of the paint I am using is left over from previous projects, and all of the cans were at least half-empty. I had enough primer and primer-sealer and EXACTLY enough black paint, but just a few spits of clear coat. I don't think any of these pieces will see any real abrasion except from being bolted/unbolted, so no real worry there.

Next I tackled getting the two holes drilled in the dash for the two newly found indicator lights. What a perfect job for a drill press! The previous day, I traced the outline of the white plastic light guide piece of the dash with all the indicator light holes. I then taped the outline to the front of the dash and lined it up as best I could. The drill worked as it should and gave me two very straight, smooth-ish holes where I needed them.

I wanted to keep the dash as water/weather-resistant as possible, so I needed to seal up the holes I just drilled with something that would let light pass through it. I would have liked silicone, but 1. it is too viscous to settle into having a flat surface and 2. it isn't completely clear, it's more like trying to look through a few mm of milk. I settled on epoxy; it flows well enough to have a smooth-enough surface and dried clear (but with lots of tiny bubbles). I put a piece of scotch tape over the top of the drilled holes on the front of the dash to keep the epoxy from leaking out, then flipped the dash over and filled each drilled hole to the point where the surface of the epoxy was flush with the plastic of the dash, and let it set for a day. You can clearly see the indicator light's color, although the "icons" in the dash are distorted. That doesn't really matter to me, I use the color and location of the lights for recognition; red light on the right side of the dash? temperature. Red light on the left side of the dash? engine is still warming up (or whatever condition I set for that light).

I attempted to make a engine block temperature sensor using one of the 10k thermistor and a ring terminal crimp (pictured). It did not work. I did successfully solder the ring terminal to the temp probe, but the probe short-circuited internally when I tested it afterward. I made another one that I jb-welded on. I'll let you know how it works once it dries.

I was trying to use the 10k thermistor instead of the 100k one that came with the aliexpress kit because when using the 100k one, the difference to the ECU between 60F and 100F is only 0.127 volts .With the 10k thermistor, the difference between 60F and 100F is 0.757 volts; greater resolution in the range we need it. The ECU can detect (I'm kinda guessing on the exact numbers) 0.005 volts change on the temperature input; each 0.005 v is one "step" of resolution. If there is only 0.127 volts between the numbers we gave earlier, the ECU only has 25 steps of resolution, or a resolution of (100-60)/25 = 1.6 degrees F per step. Whereas with the 10k thermistor, using the same 0.005 v step and 60-100 range, the ECU has 155 steps of resolution or 0.25 degrees F per step.

I'm still going to try and use the GM temperature sensors; they are much more robust than the quite-flimsy thermistors, but they are also MUCH bigger. I was intending to put one of the thermistors in the air filter to measure the IAT (intake air temperature), but there is just no way one of the GM temp sensors would work there. I asked on the megasquirt forum about remotely mounting the IAT sensor since I have essentially NO intake plenum or piping to speak of, it is literally air filter -> throttle body. I was told that remote mounting of the IAT sensor would work in my case (no under-hood area to trap heat and increase charge temperature; IAT essentially always equals ambient temp).

The place I have ear-marked for the IAT sensor is around about where I put the CDI when I had the aliexpress ECU installed. It shouldn't get heat soaked from the engine back there, and it will get some airflow over it when riding at speed. As for the engine/coolant temp sensor, I have three possible places in mind:

1. The same location the 100k thermistor is bolted to (look at my previous posts to see where I installed it). Problems with this location are I would have to drill out the threaded hole in the cylinder to a larger size to fit the tip of the temp sensor in, and then I would have to hold and secure the sensor there somehow. I really don't want to jb-weld anything to the engine. I could also make a ring terminal fit the sensor's tip and NOT SOLDER, but epoxy or jb-weld it on there. I would still have to secure it in place somehow; the sensor is too heavy to be left secured at only one point, especially on something as violently shaky as an engine. Pros are easy to access and replace, and reading the temperature of the cylinder, not the oil.

2. The oil channel access bolt next to the position mentioned in place 1. Problems with this location are having to thermally connect the temp sensor to the bolt, having to thread the tip of the temp sensor (I don't even know if there is enough meat on the tip of the sensor to be safely threaded), or having to find and buy multiple pipe thread adapters to go from the threads on the engine block to 3/8 NPT on the sensor, while having enough clearance for the tip of the sensor. Pros are easy (though not quick) access and replacement.

3. The spark plug hole. Make a CHT sensor with a ring terminal and put it between the cylinder and the spark plug. Problems with this location are, again lots o' vibration, having to jb-weld a ring terminal to a sensor, rendering it useless in any other situation, and lots of airflow over the sensor body while riding at speed, possibly cooling it below the temperature of the cylinder head. Pros are this would probably be the most accurate reading of the temperature we want, it can aid in tuning, and easy (though not quick) access and replacement.

I'm really not sure which location I'm gonna go with. Maybe a slight lean toward the current temp sensor location.

There were quite a few wires left over, unused coming from the ECU. Since I installed it (the ECU), I had a plan to wrap the unused wires together in a circle and tuck them behind the ECU. I tried to do this once by just stuffing the wires into the plastic wire loom sleeve in a circle, but that didn't work well. I had straighted the wires and tape them together about every 6-8 inches, then wound them on top on one another and taped them to each other, then finally putting the plastic sleeve over them. I seat does slightly press on the sleeve when installed and with a person sitting on it, but no where near enough to damage the wires inside.

I have been (and still am) wondering if the 125's and the 190's CDI is DC or AC. I can easily see that the 125's CDI got its power from the black switched +12v wire, but it is also comparatively smaller than most DC CDIs I have seen (from what I have read, DC CDIs need to be bigger because they need room for additional circuitry). It is only 1mm smaller than the 190's CDI. The 125's CDI has four wires/pins; trigger, ground, power, and output to coil. The 190's CDI only has one more ground pin. The wiring harness that came with the 190 would have the CDI getting AC power, and the 190 stator has a high voltage winding, the 125's stator (pictured) does not. At this point, since the 125 stator didn't have any HV windings, I am relatively certain the 125's CDI is DC (or at least works with DC). The 190's CDI... the wiring harness connections point to AC, but being the same size as the 125's CDI points to DC. I guess I'll have to try the 190 CDI on DC first (DC first because I am guessing that feeding 12 volts into something that usually needs 100+ won't hurt it, but doing the opposite will make the magic smoke escape). If it doesn't work on DC, then its on to AC. If that doesn't work, then I screwed something up.

I think I broke my cat.

We're getting close dudes and dudettes, we're getting close.

I got the gm map sensor installed without much trouble. One thing I did have to do was cut out key ways in the map sensor connector (pictured). As odd as it may be, it was cheaper to buy a clearly knock-off sensor + connector rather than just buying a connector. I bought the cheap senor/connector just for the connector, but it turns out there are different connectors for different sensors; mainly for 1 bar, 2 bar, and 3 bar sensors. The cheap sensor was a "3 bar" sensor and so was the connector. The genuine GM sensor was a 1 bar sensor. Nothing an xacto knife can't fix.

The "genuine gm" map sensor I bought did come in a acdelco box, but not the usual kind with the hologram on it. Either this is just an old-stock part and box, or the overseas sellers are getting more crafty at selling counterfeit parts. I have tested the sensor, and it does work and read as it should, so no worries thus far.

I attempted to make a holder/adapter for one of the gm temperature sensors, but failed miserably. I had a short piece of very thick gauge wire with two copper crimps on either side. I cut off the wire from the crimps and pounded the remaining bits of wire with a hammer and a punch in a vise. Then, I TRIED to re-open the two "jaws" that held the wire in place, but the copper was too work-hardened from being crimped, and I just mangled the whole thing. Oh well, I tried.

The temperature probe I jb welded on to a ring terminal worked out very well, and until I find a good way to mount the gm sensor somewhere to the engine, I'll be using it as the engine temperature sensor.

I also bought 5' of 3/16 and 5/16 fuel hose to use for all the low-pressure fuel runs, along with a fire extinguisher, gasoline-resistant sealant, various ratings of fuses, a bar clamp phone holder, and a 5/16 quick connect to 5/16 hose barb adapter. The fuel hoses are self-explanatory; I don't have an anti-gravity pump so I have to use hoses to move fuel to and from the gas tank. The fire extinguisher is, I hope, even more self-explanatory. I want this engine to remain an INTERNAL combustion engine. The fuel-resistant sealant is because when I took the fuel level sender off of the tank, I noticed that the rubber sealing washer was put in incorrectly and pinched (pictured). I don't know if that will cause a leak, but I am going the safe route and adding sealant. Fuses; so I only have the good kind of sparks. The phone holder is so I can connect the microsquirt to an app on android that gives me a choice of a few dashboards with most pertinent information easily read while I am riding. Don't worry, I have an old pre-dropped phone I am going to use for the dash display. The quick connect to hose barb is for connecting to the high-pressure side of the fuel pump. I mentioned in a previous post that the outlet on the fuel pump is supposed to be used with quick connect fittings, not with bare hose. The adapter is the necessary piece to go from the fuel pump to the high-pressure fuel hose. Note that they are called quick CONNECTS, not disconnects. You either need a special tool to disconnect these, or do what I did and buy one with a button you can press to release the adapter.

I was going to use the existing barb on the top of the fuel tank for the fuel return, but I just couldn't stop thinking that since the fuel hose going to the pump from the tank and from the pump back to the tank are the same size, if there were even a little bit of flow restriction on the return hose or the fittings, the fuel wouldn't be able to go back to the tank fast enough and cause higher-than-intended pressure on the high-side of the pump. Using a larger size hose along with larger fittings on the return route gives lots of room for high-flowing fuel. I chose a location on the tank that wouldn't be too far from the pump and not interfere with the plastic tank fairings. Mostly because of the inability to reach any other place in the tank, I chose to drill a hole near the rear of the tank, about an inch above where the tank fairing ends. Drilling the hole went without problem. I used a 1/8 npt female-female coupling, 1/8 npt male close nipple (yes, that is the correct term), a female-female 1/8 npt 90 degree elbow, and a 1/8 npt male to 5/16 hose barb adapter to make a clamping bulkhead fitting that hopefully along with jb weld will make for a leak-proof fuel tank return connection. I had to sand some of the paint off the tank to get a good bond with the jb weld. I ran out of black paint when I painted the license plate and exhaust brackets, so I had to use white touch-up paint (not pictured). The color mismatch doesn't really bother me, it is under the fairing so it won't be seem unless the bike is being serviced and the paint color wasn't chosen for aesthetic purposes, it's just what I had laying around.

I mounted and connected the gm temperature sensor that I am going to use for the intake air temperature. I chose the place I mentioned in the previous post, where the aliexpress CDI was installed. I had completely forgotten that there was an open-mesh air vent in the fairings right there. That means that the sensor will be getting at lest some airflow while riding at speed.

I connected the two "new" dash lights and they are now controlled by the ECU. The temperature light will come on if the engine/coolant sensor reads above 190F/~87C. The check engine light will come on when rpms are > 0 and the warmup fuel enrichment is >100% (100% is the calculated required fuel; 200% or 300% would be fuel added for a cold engine).

I still want to use the ignition advance inside the CDI box that came with the 190, but it is looking like almost every way I can think of using it is met with an problem that prevents me from using it.

Way 1. Go back to carb and CDI. Hahahah NOPE.

Way 2. Use the microsquirt in fuel-only mode and let the CDI control the spark timing. This one is the most promising, but there is one major problem; the crank VR sensor is the only way I have to sense the engine's position and speed. The CDI needs to use the sensor as its trigger, but the ECU also needs to use the senor to determine rpm. So both need the sensor's output, but the ECU cannot share the signal with the CDI; the CDI has a shared ground connection with the spark ground, power ground (circuitry to drive the CDI), and trigger signal (VR sensor) ground. So one lead from the VR sensor will be grounded (inside the CDI) to the same point that the spark plug and EVERY other power device grounds to. In the microsquirt manual, they warn about letting this very thing happen. It WILL cause bad interference with the rpm signal. Until I find a way to either split or isolate the VR sensor's signal, this option is no good.

Way 3. Give the microsquirt a completely flat ignition map, EVERYTHING set to 0, let the ECU output a signal exactly when it gets a signal from the VR sensor, and use that signal from the ECU to trigger the CDI to fire the spark plug. This would work, except the 190 CDI and every other CDI I have except for the one from aliexpress doesn't respond to logic-level inputs (usually 3.3v to 5v, low current) from the ECU. So unless I can find a way to drive the CDI from an ECU output, this option is not good.

Way 4. Extract the timing information from the 190 CDI and use it in the microsquirt ECU. The only "real" input the CDI has is the trigger from the crank and the only output it has is the ignition coil drive wire. The closer the trigger pulses from the crack are to each other, the faster the engine will be turning. If the engine is turning faster, it will in general, up to a point, need more spark advance, so the spark will happen closer to when the CDI gets its trigger input. By measuring the time between the input pulse (crank VR sensor) and the output pulse (ignition coil) at a given frequency, you can calculate what the spark advance will be for that given frequency.

In practice and as mentioned above, the CDI units do not respond to logic-level inputs. Also, the voltage signal from VR sensors goes positive and negative (above and below 0 volts). By themselves, the ECU and the arduino I was using to produce the frequencies, cannot drive a pin to below 0v. I do not have the necessary circuitry to make a negative-going signal, not to mention that the trigger circuitry inside the CDI might not even be driven by voltage, it maybe driven by current (as some of the earlier megasquirts were).

Unless I find a way to make the ECU and CDI cooperate and/or successfully extract the timing information from the CDI, I will have to use a pulled-out-of-my-ass, very conservative spark map on the ECU.

All that is left before I can do a test fire is to route the fuel hoses, take the bike outside, test/leak check all hoses, tank, pump, and fittings, and mount the exhaust.

Saturday, Sunday, and Monday are supposed to be above 60 degrees. I am cautiously and reservedly crapping my pants with anticipation and excrement. I mean excitement.

on the positive/negative signal, is it possible that the signal is going negative due to the inductive field collapsing, and causing a reverse voltage spike?

Yes, VR sensors by design, use that collapsing field and reversing voltage to give a very precise, short, sharp polarity change exactly when the center of the little "magnet bump" crosses the center of the sensor. A microcontroller with signal conditioning circuitry can use that zero-crossing point as a very accurate timing trigger.

Small update.


My ADHD-induced fyper focus (focus on something so much, so hard, and for so long you literally forget to eat) has already made me miss a meal, not realize that my hands are so cold I cannot type very well or fast. That is how much I am simultaneously drooling with excitement and pooing my britches with anxiety.


I got the bike out of the house; had to go through the patio door and the backyard. I got the tank filled with fuel. No observable or touchable leaks. Lots of fuel odor, so finding a leak with my nose will be impossible. Fuel pressure gets up to about 40 psi and stays there while the pump is running. When the pump shuts off, it instantly goes back down to about 25 and then over the course of about 5 minutes goes to 0. There is definitely some air trapped in the high-pressure side; that is going to be a recurring issue with the dead-head fuel line to the injector.


With my laptop recording, fire extinguisher nearby, but not within fuel-leaking range, fingers crossed I turned the engine over.


BANG!


An air/fuel charge was ignited within the engine, but with the intake port still open some amount (or opened shortly after). Sounded like what I imagine a gun shot sounds like. My guess is incorrect timing, a spark that was triggered by noise on the crank VR signal, the ECU unable to correctly calculate engine rpm, and fired the spark plug sometime when it wasn't supposed to, or the ignition coil going into "save the coil mode" where it will fire the spark plug if the ignition coil has been charging for >~8ms.


Through some change-something-and-see-what-happens troubleshooting, I got the noise on the crank VR signal reduced quite a bit. I tried cranking the engine again.


The engine turns over, but doesn't fire.


The spark plug is firing (and yes, I did remember to screw the plug back into the engine). I noticed that the MAP sensor is only showing about 67 kPa. Either the decompression valve in the 190 might be messing with the MAP reading, or the way the ECU is calculating the MAP signal is wrong (since this engine has effectively no intake plenum, the pressure/vacuum inside the intake manifold changes with every stroke of the engine, with next-to-no mechanical smoothing that a large volume of space would cause.


I'll have to mess with the ECU's MAP sensor readings tonight/tomorrow.


I have been cranking the engine over quite a bit as well as restarting the ECU. That means a lot of "priming pulses" of fuel were sent into the intake manifold. Maybe enough to flood the engine. The microsquirt has a flood clear mode which I have enabled; it will not inject any fuel into the engine when the throttle is held above 70% while cranking. I held the throttle wide open and cranked the engine.


BANG!


Apparently in flood clear mode, the spark plug still fires. That seems a little... odd.


At this point I realized my stomach hurt, my hands were shaking, and I couldn't think straight. There's the hunger and cold my body has been trying to get my mind to realize. I went inside and made a sandwich and sat down to write this post and do some research on if there is ANYWAY to get a CDI to work with the microsquirt.

From the sounds of things, could your timing be 180° out? I forget what all you are using for timing, i know most megasquirt builds in the car world use a crank and cam signal to verify engine timing... are you using just the crank trigger or? Im not too familiar with the microsquirt and what all it wants to see... its been a few years too since i was investigating MS for my truck...LOL

Also, i dont see why a cdi WOULDNT work with MS... how many people run aftermarket ignitions in thier cars with MS... most of them run accel or msd ignitions... however, i wonder if the built in timing curve of the cdi for our motors is throwing things out... i wonder if you need to just run a coil driver off the microsquirt, straight to the coil... or like previously mentioned run the ms for fuel only, and use the cdi somehow isolating the signal between the 2...