A hot day in the sun and a mild sunburn later, I finally have the AFR gauge installed and wired up! According to the too hot/too cold LED indicator from the wideband controller, the o2 sensor reaches operating temperature in about 20-30 seconds after power-on. Freshly started and still on choke, the engine will be around 13ish AFR going down to low 12 AFR at idle. Adjusting the idle toward ideal mixture (14.7) makes the idle smoother and less burbly. I think I'll need to go down one size on the pilot jet to a 38; with the air mixture screw on the carb out 3 1/2 turns, the engine was still running around high 12 AFR.
One thing I quickly noticed is that I underestimated how bright mid-day direct sun is - the numeric AFR display is visible if you focus on it for about a second and the AFR indicator LEDs are somewhat visible except for the yellow ones - those are nearly impossible to see. Oh well, it doesn't really matter to me all that much. As long as I have a working AFR gauge of some sort, I'll be fine. In fact, the difficulty is seeing the gauge was probably for the better; if I could have seen it clearly just be glancing down at it, I probably would have been looking at it too much and not keeping my mind on the road.
I took the bike out for a ride after the gauge wiring was done. Throughout the entire RPM range, the engine stayed in and around 13 AFR except when I did a acceleration run on a lonely country road. With the bike in 2nd gear at about 4k rpm, I twisted the throttle wide open. The AFR went down to 12.x and climbed back up to about 13.5 as the rpms rose up to 10k rpm.
I realized in that ride that I really need a good... 3 or 4 hours in a parking lot so I can practice my low speed and start-from-a-stop clutching. However, to do that I'll need better headlights. As it is now, at night the high beam's illumination range is 35ft... maybe. I don't know if these headlight housings can handle the temperatures of halogen lights; the scooter I have has a headlight holder that would melt if you used anything hotter than the stock headlight. I can do the usual replacement of the LED headlights, or I could do/make something that might work better! (or possibly much worse)
I've been tossing this idea around in my head for a few weeks now - ruckus-styled headlights on my grom clone! I don't remember exactly how the idea got into my head, but it's there and it's staying! If you don't know what ruckus headlights look like or can't imagine it on a grom clone, here are two links to
drow sports and
steady garage where they have pictures of ruckus headlights installed on a grom and a lil duc grom clone. Remind anyone of The Dirt Bike Kid?
I won't be using genuine ruckus headlights as those are >$200 for the whole headlight assembly, nor will I be CNC routing a piece of aluminum (oh how I wish I could, though). I'll most likely be using flat either steel or aluminum strips. I have a very rough mental idea of how I will bend the metal into the frame for the lights, I can't really put it into words yet. If I do make this headlight assembly, I'll have to do something to cover up all the ugly wires and connectors that are behind the headlight housing already on the bike. All of this will probably be my
next project, I have one that I am just finishing up (and yet another on the side) -
Quieter exhaust! Hopefully! I bought two muffler re-pack kits from amazon; one with just a very thick ceramic packing sheet and another one, more of a includes-everything kit with a stainless steel screen, stainless steel wool, stainless steel wire, fiberglass packing material, rivets, and #00 and #3 steel wool for polishing/cleaning. You can see in one of the pictures everything that is included in the kit on the pink box lid, the thicker ceramic packing material is next to it in a zip lock bag. My intent was to use everything from the all-in-one kit except for the fiberglass packing material - I used the thicker ceramic packing material.
Getting the rivets out of the muffler wasn't too hard. I don't think they were stainless steel, though. They didn't spark at all when I ground them off. Nevertheless, the rivets were removed. Now, I had to somehow pull the end cap/baffle off of the muffler without going ham-fisted on either. I had to drive a screw driver between the baffle and the muffler to break the silicone seal. Then I ended up bending a small piece of steel that once was one of those cheap wrenches you get with flat-pack furniture into a flat bladed screwdriver-ish-looking-thingy and pounded that between the baffle and the muffler and when I pulled it out, the baffle came with it.
The packing material that was in the muffler looked kinda cheap and had already started to... I'm not sure if fiberglass burns, but maybe just degrade from constant exposure to extreme conditions, but I don't really have enough knowledge about packing material to say for sure. What I can say for sure is that the packing material wasn't completely filling the muffler, so there is at the very least a small gain to be had by repacking the muffler... after only 120 miles.
I started repacking by cleaning up the perforated muffler core with the steel wool that came in the kit. After that, the stainless steel screen was wrapped around the core (not easy; stainless steel doesn't bend like meant-for-keeping-bugs-out metal screen does, and you WILL impale yourself at least 3 times on the stray wires). The wire that I used to secure the stainless steel screen isn't stainless steel - you can see the rust on it. I had to use something to keep the screen from unraveling. The muffler core is steel and is already rusting. The core and the wire are the only two non-stainless pieces of metal in the muffler (excluding the silencer), and are relatively easy to replace. I can live with the inside of my muffler rusting out a wee bit quicker if it means a much easier time assembling it now.
Next on the wrap was the stainless steel wool. This was fine strips of SS about 1.5mm across and... .003" or .004" thick (very rough guesses) matted together in a roughly common direction. Kinda like chip board. I needed a sacrificial set of scissors to cut the wool to size, as well as cut the ceramic packing material. I still had enough to do close to another entire muffler once I cut off what I needed. I used one single wrap around the perforated core - no overlap, just the screen and the SS wool are as thick as the old packing material was. While wearing kitchen gloves (I was already impaled, I didn't want to be lacerated) I tightly wrapped the SS wool over the screen and secured it with the SS wire from the kit.
Next up was the fluffy packing material. This stuff is sold as 1" thick and it is, but it can be compressed easily and readily. I could only put one wrap of the ceramic material around the core. I used blue painter's tape to temporarily hold the fluff in place while I twisted, shoved, and squeezed the whole wrapped core in to the muffler. I took the painter's tape off as I pushed the core in, I didn't leave any tape in the muffler. And then I forgot to put some kind of sealant on the baffle before I pounded it home. I was feeling lazy after having put the whole muffler back together, so I did what lazy-me does in these cases. I squirted sealant around the seem on the end of the muffler and poked some of it in-between the baffle and the muffler, then wend back around the seam again with more sealant to fill in and holes there were from the poking. Getting that baffle off the muffler was not fun, so if I can seal the muffler without effectively gluing them together I'll do it. The sealant has to set for about a day, so no vroom vrooms yet.
Now on to the second part of making the exhaust quiet, modifying the silencer.
I look online at cross sections of OEM car and motorcycle mufflers and most of them use 90 and 190 degree bends to dampen sound with minimal back pressure increase, along with sections with perforations and narrow-pipe choke points. I used some of these designs in a modification to one of the exhaust silencers I bought previously. I wanted the exhaust to go around at least 2 90 degree bends, preferably 4, and at least one section with perforations. I had to ride my bicycle to the hardware store, but no biggie, I needed the exercise. I bought two each of two different stainless steel sink drains that fit inside the exhaust silencer. One fits neatly inside the larger end of the silencer, and the other fits almost perfectly on the end of the larger end of the silencer. It turned out that I didn't need/couldn't use the larger ones, but I had opened the packages and mangled them before I found that out. Oops.
I don't think I will be able to explain in words how I expect the exhaust to flow through the silencer, so we'll both have to suffer through my poor illustration. I chose blue to represent the engine's ass gas. I don't know why.
The very nearly final order of assembly (pictured; left to right, top to bottom) for the additions to the silencer are:
Threaded rod bolted through the blocking piece on the small end of the silencer
Threaded rod comes through to larger side of silencer with backing nut for
First perforation section (with two rows of holes along the sides, difficult to see) to be directly riveted to
First blocking plate, secured with nut. Then comes
Second perforation section, spaced apart from first blocking plate with nut. Finally,
Third perforation section/second blocking section/keep-it-all-inside end bit, secured with two nuts
I tried to design this so each piece could be taken out and repaired/replaced easily; nothing is welded or adhered in place (although time and heat may effectively weld the threaded rod and nuts together), and the rivets can be drilled out or ground off. I have already cleaned and primed the two pieces in the silencer that are clearly not stainless steel with exhaust header primer and will be painting the larger of the two black with high heat enamel spray paint. I'll have to sure the painted piece in an oven at a few different temps. I'm not going to use the household one for obvious reasons. I do have a small toaster oven in the garage with lots of metal sheets that fit in it. I think (I REALLY don't know, but I think) if I shield the exhaust silencer piece from heat directly radiated from the heating elements and only let convection heat the silencer piece, the paint should cure as it is supposed to. Plus, even if the black paint doesn't work for some reason, all of the parts in the silencer are directly exposed to the soot from the exhaust gasses. A few rides in, and everything will be black whether you want it to or not.
That brings us to now. I am going to be painting and curing the pieces soon. I haven't yet started the engine with the new packing yet.
No progress has been made on the quick shifter project; I prioritized not worsening my tinnitus over a possibly working way to increase 0-60 times.
Oh and one more VERY small bundle of joy pictured.