New Lifan X-Pect Mechanical Woes!

[Overland Adventure]

* * I repeat myself a lot in the video, I apologize. I'm so stumped and frustrated that I think out loud a lot, and end up saying the same thing several times. Sorry in advance! * *

* * Note #2: If you don't have time to watch the whole video, skip to 18:05. That's when it starts to act up. Before that is me describing what trouble shooting I've done so far, and footage of the bike driving fine with plenty of power showing that the issue it has is not all the time, but only after whatever mystery conditions are met. * *


New Lifan X-Pect, less then 100 miles. After several miles of riding, it starts to cut out/die, then suddenly have power again, then die, over and over. When it does this it feels like your at wide open throttle, climbing a hill or what have you with no problems, but someone is turning the key on and off at random. It'll be fine and have power for a few seconds, then dies and start coasting, then have power again, then die, over and over. Any ideas?

The KPM200 at the beginning on the video has a warning light that goes off if it starts overheating, anyone know if the X-Pect has one too? I'm wondering if the bike is overheating since I am giving it 'the beans' for several miles when it stats to mess up - maybe there is a temp sensor that tells the ECU to cut the fuel, or spark, or something else when it detects an overheating situation (to try and 'save itself'? A 'Limp Mode' if you will. Maybe that would explain why the bike is fine for quite a bit, then presents an issue after it's been WOT for a while?

[Ina Ditch]

I hate that you are having this problem and wish that I could help you but I bet someone here will be able to. I guess this is where we find out if your seller and /or Lifan America can be counted on.

Keep us posted on how things transpire.

good luck.

[Jsalmi]

Hi, never had anything like this on mine. Just cracked 500 miles today, but mine did like to stall after running hard and coming to a stop in the first 200 miles. In more detail, I would run wide open for a while, then at stoplight it would idle fine and 10 seconds later die. Now still a few times, but I anticipate it and with throttle and have turned idle to 1800 on the tach.

[Ina Ditch]

Jsalmi, have you reached out to your dealer or Lifan? After I replied to Overland Adventure I went through the first six pages of google search results for a search of Lifan motorcycle parts and found nothing substantial.

the xpect was on the top of my list but I am sure second guessing myself now.

I will be watching this with interest.

[Rocket tests]

Is there any place to hook up a fuel pressure guage and a continuity light on the fuel pump wires?

[culcune]

There haven't been too many X-Pects here, but with Chinese thumpers, it seems some come from the factory with tight valves. I know many members' Hawks have come tight and doing a valve lash adjustment has solved the engine cutting-out problem. I would contact Lifan tomorrow if they are open and see what they have to say. Perhaps it is a ECU defect and they can send you a new one. Also ask them what the settings should be on a valve lash. Also, check the spark plug if you haven't done so.

Edit: commented before watching video (disclaimer, still have not watched entire video) so you did look at plug. What about valves (did I miss that?)?
2nd edit: Assuming all the electronics are fine, I am guessing if the valves needed adjustment, it wouldn't show as an error.

[Overland Adventure]

Originally Posted by culcune

It seems some come from the factory with tight valves. I know many members' Hawks have come tight and doing a valve lash adjustment has solved the engine cutting-out problem.

After reading your comment Culcune I did some browsing around and found MANY people saying the same exact thing. I don't know if I will be able to do this today (I have to go out and buy a set of feeler gauges) but I will be checking the valve lash soon, and posting my findings as well as what the factory specs are supposed to be.

Originally Posted by Rocket tests

Is there any place to hook up a fuel pressure gauge and a continuity light on the fuel pump wires?

I could cut the fuel line and put a pressure gauge inline, and strip insulation off the wiring and use alligator clips and a multi meter there. It wouldn't be pretty, but it would be effective. I'm going to check the Valve Lash first as that sounds like something that should be done regardless on Chinabikes, and if that doesn't work then I'll start breaking out the fuel pressure gauge and multi meter.


It may not be today, but I will post my findings soon. Thank you for all the input everyone!

[Red Hawk]

Next time it surges like that open the gas cap lock it Shut again see if the tank vent is pulling a vacuum. Just a chance but I had this. Sounds like something to do with fuel pressure. Past that you’ll need a multi meter to trace down this glitch.

[Larky]

I will admit I don’t know much about the fuel injection system on these bikes, but I would assume they have a throttle position sensor. After watching your video, that was the first thing that came to mind. As if the system is being told that the throttle has closed. Checking the valves is a must no matter what China bike you have. And besides the purchase of the feeler gauges, it’s free. When troubleshooting I always go for the easy simple and cheap/free approach. Like cleaning electrical connections, verifying valve adjustments, using a test meter on the electrical system. Just verifying what is NOT the problem. That way I can narrow down my approach in stead of throwing money at it.

[deadwood83]

My hunch is that they don;t build different motors for the different 200CC EFI bikes but rather change the sprockets. Looking at the KPR manual (the only one I could find online) shows valve lash set .03 to .05mm which seems to match up with most other CN thumpers (and is the target range for intake on my 82 XJ650 as well).



There should also be a 4-wire diagnostic hiding somewhere on the bike, either back right like the KPR, or possibly left side just astern of the petcock assembly.



From Small Engine Velocity's Video:



There are four common ODBII protocols. If your multimeter can read PWM/RMS signals (fluke 115 or better) you can measure out the voltage levels compared to ground and figure out the data transmission type per this page:
www.onboarddiagnostics.com/page03.htm
Mix of 5V and 0V - J1850PWM
Mix of 7V and 0V - J1850 VPW
Mix of 12V and 0V (on the signals) - KWP2000/ ISO9141-2
Mix of 3.5V and 1.5V - CAN


Then you can put a Bluetooth OBD2 on a 4-pin adapter wired appropriately and watch realtime diagnostics as you ride from Torque or other app of choice.

Of course, any findings should be directly applicable to your KPM as well.


That said, your comment on sitting for a significant period of time would indicate the valves may be too tight.

- Valve expands with heat > engine loses compression and won't fire
- Air/fuel wash cools it just enough to make compression since valve is not sealing so piston is pumping "flammable coolant" over the valve
- Valve cools leading to brief period of firing
- Valve heats, expands, loses compression, cycles continues.


Oh and to answer your original question, coolant temp sensor is here:



I expect my brother's KPM to arrive soon so I may have a vested interest in your results. Let us know!

[franque]

I'm guessing something electrical, I would make sure that all of your grounds/connectors are tight, and double check the charging system. It could be the TPS, looking at that. I'd pay specific attention to the connector, and the wiring therein.

You might have to look the entire wiring harness over to find the problem. It could be the valves, but it doesn't sound like it. That being said, let the motor cool off for a day, then check the valves. I believe those valve clearances quoted above might be too tight, I'd defer to the conventional .05-.08mm instead.

[Overland Adventure]

Originally Posted by Red Hawk

Next time it surges like that open the gas cap lock it Shut again see if the tank vent is pulling a vacuum.

Holy smoke this is an amazing idea, thank you! If nothing else, it'll help eliminate possible culprits and help narrow down troubleshooting steps. Heck it may be the culprit - we shall see! Thanks man!

Originally Posted by franque

I'm guessing something electrical, I would make sure that all of your grounds/connectors are tight, and double check the charging system. It could be the TPS, looking at that. I'd pay specific attention to the connector, and the wiring therein.

You might have to look the entire wiring harness over to find the problem. It could be the valves, but it doesn't sound like it. That being said, let the motor cool off for a day, then check the valves. I believe those valve clearances quoted above might be too tight, I'd defer to the conventional .05-.08mm instead.

I have a copy of the owners manual, I'll post the specs in a little bit.

Originally Posted by deadwood83

Then you can put a Bluetooth OBD2 on a 4-pin adapter wired appropriately and watch realtime diagnostics as you ride from Torque or other app of choice.

I found the test plug on the X-Pect no problem, it hangs out above the fuel pump. I'm going to order a Bluetooth OBDII reader off of Amazon now. This will be interesting to see what's happening in real time.

Originally Posted by deadwood83

That said, your comment on sitting for a significant period of time would indicate the valves may be too tight.

- Valve expands with heat > engine loses compression and won't fire
- Air/fuel wash cools it just enough to make compression since valve is not sealing so piston is pumping "flammable coolant" over the valve
- Valve cools leading to brief period of firing
- Valve heats, expands, loses compression, cycles continues.

Strong theory. Hopefully today or tomorrow I will be able to obtain some feeler gauges and see what everything is at currently.

Originally Posted by deadwood83

Oh and to answer your original question, coolant temp sensor is here:

Went out and found it on our KPM and labeled it with a fine white paint pen 'just in case' in the future. Fortunately, knock on wood the KPM runs like an absolute champion at 200 miles on her so far, only the X-Pect is acting up.

Originally Posted by deadwood83

I expect my brother's KPM to arrive soon so I may have a vested interest in your results. Let us know!

He will LOVE it. The KPM200 is definitely a top shelf Chinabike. It feels like a real attempt from Lifan to compete with 'brand name' bikes. The fit/finish/quality is impeccable, the 6 speed transmission really helps this thing be a practical, truly dailydrive able bike on 55 - 65 MPH roads in completely stock form. The Fuel Injection is very responsive and so smooth across the RPM range. I forget its only a little 197cc bike when I'm cruising at 65 MPH no problem. I love it, my wife loves it, definitely a great decision on buying it. Your brother is going to enjoy the heck out of it.

[Goob]

Even though you may not have bought your bike from them, I have a gut feeling (just from looking at so many seller sites) that maybe you could turn to Venom Motorsports USA for some help.

[Jsalmi]

I did the actual valve inspection this morning. Cold engine from overnight, Craftsman 32 blade feeler gauge used. Exhaust .06 mm and intake .04 slid in and out without resistance, I followed instruction on CSC TT250 manual per line. After turning up the idle to about 1800 I have driven to work (6 miles each way) 3 days no stalling at 580 miles.

CSC Repair Manual for TT250

So, with all that theory behind us, let’s consider what we’re going to do here:

We want to gain access to the valve rocker arms and their adjustment screws.
We want the engine to be at a point in its rotation such that the rocker arm is on the cam’s base circle. This means the cam is not actuating the rocker arm. We want the engine to have the piston at (or very near) top dead center, which means the valves should be closed (which is another way of saying the rocker arm is on the cam’s base circle).
With the engine in this position, we want to loosen the threaded adjustor lock nuts, we want to set the valve gaps to the specified gap of 0.04mm to 0.07mm, and we want to tighten the lock nuts to lock the threaded adjustors at this gap. We always make the adjustment to the 0.07mm setting. As the valve and the cylinder head wear, the gap will grow smaller. Setting it to the 0.07mm setting allows us to keep the valve adjustment interval (the number of miles you can ride between valve adjustments) at a reasonably high number. Initially, we’re establishing this interval to be 500 miles for the first adjustment, and every 2500 miles thereafter.
When we’ve completed the above, we want to put everything back together.

[bmw111]

Simple suggestion -- check your battery cables to see if they're secure. And all other electrical cables/connections.