[Cforcequad]

I have been sharing information with a dealer in Minnesota who has been working with CFMoto headquarters regarding the stalling when hot issue.  He has informed me, based on information owners have been providing, CFMoto has been able to reproduce the issue during their tests.  CFMoto is researching a revised TMAP sensor, a modified gas cap and possibly other things but I do not believe there is a formal solution as of yet. 

I agree with the previous post.  My experience has been the XC is a joy to drive and takes you where you want to go minus this somewhat hard to recreate stalling issue (does not happen all the time or every ride, it seems to only happen on hotter days during longer rides).

Keep providing information to your dealers with as many details as possible.  The dealers and CFMoto appear to be listening.

Hi, I had similar problems on "Carretera Austral", I blamed the change of octane at a gas station, thinking that the sensor recognized a change in the ignition point. However, after changing to normal octane, the problem was repeated a few times.
After driving more than 1500 miles on that trip, I think the problem is that the sensor shows a non-existent problem, is annoying and can hide a future failure.  If I should bet, after deciding to stop every hour and a half and let the engine cool down, the code disappeared, perhaps the sensor is affected by high temperature.

Greetings!

[30Carbine]

I have had conversations with three very helpful CFMoto dealers that have had conversations with CFMoto headquarters regarding the elusive stalling when hot drive-ability issue.  It is my understanding from speaking with them that CFMoto has been able to reproduce the issue and is evaluating the root cause so they can determine the proper fix.  The most likely cause being pursued at the moment is that some units may have had their valve clearances set a hair too tight at the factory.  Therefore, when things get really hot, the affected valves expand and do not completely close causing the misfires / stalling.  They have loosened the valve clearances to be clearly in spec on only a few machines experiencing the issue at this time and it seems to have corrected the problem.  However, with so few machines where this adjustment has been made and the difficulty of creating the issue (i.e. long rides on hot days, up and down hills with two riders on board) I do not believe CFMoto is declaring victory until they see more machines where the valve adjustments have truly resolved the issue.  The dealers I spoke to indicated that CFMoto is interested in seeing more machines exhibiting the issue so the valve clearances can be checked and adjusted if needed to see if the problem clears up in larger numbers of machines.

[Cforcequad]

Nothing to say, It is a very reasonable explanation. Thanks.

[danoduke]

Update:  I've driven over 100 miles since my ECU re-flash.  Outside temps have been a little cooler but I drove it hard and didn't experience any further stumbling or stalling.  So far, so good!   

[engineereskimo]

Dealer tech here again, can confirm that valve clearance took care of the 800xc i had that was showing the hot stall issue. When inspected the front cylinder was in spec but the rear cylinder had no clearance at all. Before, unit would shutdown in aprox 15-20 miles. Now, cust took and put almost 80 miles round trip with no issues. Have your valve clearances checked if you have already tried the reflash and the TMAP replacement. Will update if it shows back up. Good luck all!

[30Carbine]

Thanks for the update engineereskimo.

Your experience with valve clearances appears to support CFMoto's current theory of the root cause of the "hot stall" issue.  Please do keep us posted.

I will vouch for the fact that this is a hard issue to declare victory on as I have a unit that had the ECU flashed for the P0172 error issue and it experienced a "hot stall" event after the re-flash.  That said, my "hot stall" after the ECU re-flash only occurred once in 290 miles which were logged over multiple rides averaging 20 to 50 miles each.  Additionally the "hot stall" occurred only on the hottest day it was ridden.

[eg78]

Well, it finally happened. P0172 on a hot day right after going up and down rock hills in low 4wd it would stall with the code. Finally I held down the SEL button which cleared the code and it didn't stall after that. Not sure if this was coincidence but worked for me. I'll still have the valve clearance checked by the dealer.

[Milehitaz]

I just bought a 2019 cforce 800 xc. Its been back to dealer twice now.... Its 2 weeks old. It has 54 miles on it. At 20 miles into each of my two rides, it will not come off idle. Often times it has no power as throttle is opened then explodes with a burst. Otherwise it is a complete stall out.. Fast restart but it gets to be every time u hit the gas it craps out. Service is doing major work and i hope to get it back next week and take a long ride.

[doug80638]

My Brother's XC had the same issue (though perhaps not as severe as what you describe),  and the dealer worked with CFMOTO to get it fixed.

[eg78]

Dealers fix is to replace ECU. It's being replaced right now. Reading through this, Im not sure it's going to fix the issue but time will tell. I probably wont know until next summer when it's super hot again.

New issue - The brakes squeel like crazy. Anyone else seeing this? Dealer said I was the 3rd person to complain.

[Chris57]

Any updates on the P0172 / heat / ECU saga?
My ECU was replaced, running well so far but the weather is a lot cooler. (Although I always find the motor running hot, not showing anything wrong on the gauge, just lots of heat running up to the rider area)

[eg78]

Any updates on the P0172 / heat / ECU saga?
My ECU was replaced, running well so far but the weather is a lot cooler. (Although I always find the motor running hot, not showing anything wrong on the gauge, just lots of heat running up to the rider area)

Im in the same boat, ecu was changed... now I need to wait till next summer to see if its fixed, way too cold out now.

[Srkennedy]

I took a 2000 dollar hit and traded mine off. I couldn't trust it to get me back home anymore. 2 out of 3 of the cforces I've owned have had problems. I'm done with them.

Oh, my issue wasnt fixed and there was nothing in the future that indicated they were any closer to a solution.

[Sheem2153]

Myself and 2 other friends each purchased a 2019 cforce 800xc. Today was the first time that we really got to ride them for more than 15 mins. Rode for about 3.5 hours putting about 30 miles on each. After about 2.5 hours they started experiencing the hot-stall Issue. All 3 were acting the same way. We will be going to the dealer this weekend to ride them hard until they start acting up. We shall see what they outcome is.

[30Carbine]

Sheem2153, I don't know how big or highly ranked your dealer is but I would check with them to see if they can arrange to have a CFMoto representative on site while trying to reproduce the issue.  I believe CFMoto would be interested in seeing 1st hand a few machines being run under conditions where this issue is reproduce-able.  Based on my direct experience with this same issue, CFMoto and my dealer has been super responsive in trying to address this issue and my machine has had an ECU re-programming, valve clearance adjustment and some fuel system EVAP line routing changes and my machine seems to be running good after these changes.  That said, my valve clearance adjustment was done later in the riding season up here in the north east region of the United States so I have not been able to run it under hotter summer conditions when the issue is most prevalent.  CFMoto currently believes the valve clearance adjustment is the true fix as the machines they have seen with the issue have had clearances that were set too tight (under spec.) from the factory.  That said, I believe they are still interested in reviewing additional examples of machines with the issue as I am not sure they are fully ready to declare victory related to the issue with what they know today as the problem is somewhat elusive and hard to recreate after a repair is attempted.  Good luck and keep us all posted.