08 Arctic Cat M8 engine stalling

[smurferdude]

I am running an 08 M8 with MBRP can, speed works air intake and vent kits. The problem I am having is that it keeps stalling out on me. At first it seemed to happen only when the fuel tank was full and while doing long steep powder turns, now it will stall out at any speed and any time. When it starts to stall it comes on slow. The motor will lose power and start to sputter, then it will either shut off or sputter for a while with RPM's dropping to only a few hundred followed by the gauges reseting and everything running back as normal. When the motor does sputter and stop running it starts right back up and runs good with one pull.
This weekend I had to get towed off the mountain because it stalled out and would not start up again. After towing it about 1/4 way down we stopped for a break, I gave her a pull and it started right up again, put the belt back on and drove about 200 feet and the motor stalled out again.
I run 91 octane all the time and Arctic cat 2 stroke oil, the plugs are changed every 500Kms. Power valves were cleaned and cables measured one week ago.

If anyones has any idea of what this problem might be... please let me know. At this time I am thinking maybe the micro switch on the throttle return pressure switch?

 

[unit116]

I know this is an old post, but did you ever get any resolution on this. My 2007 m8 is now doing the same thing. Any help would be greatly appreciated. Thanks.

 

[Chalifunk]

I know this is an old post, but did you ever get any resolution on this. My 2007 m8 is now doing the same thing. Any help would be greatly appreciated. Thanks.

Did either of you get this problem fixed with your machines? My 2008 Arctic cat M8 is doing the exact same thing. I have new plugs, fresh 91 octane gas, fresh arctic cat oil, and have had Specialty change out the wiring harness, as they said that was the issue... I took it out after the wiring harness was changed and it ran well for the first few hours then it started stalling but would fire back up, then half way through the second day of riding it stalled and would not start again. Im not sure what else to try? Any help would be appreciated. Thank you.

 

[bdietz]

I have had this happen to my 2011 HCR. it did it a couple times once it started right up another time pulled the rope many times and finally it went and also had it almost die a couple times but then it took off
im thinking fuel air lock or something because the one time it wouldn't go we checked for spark and was good

 

[plio7]

kind of interested in this issue myself, mine did this one day after platying in some powder, kind of chalked it up to taking in some snow, it cleared up and hasnt acted up since, but would like to know more if it should come up again.

that said the day after it happened to me before riding i pulled the air intake and banged out some ice build up....cleaned out what ever i could from down in the bottom of the cavity under the intake.....not sure if maybe that build up was the issue

 

[0neoldfart]

You have an electrical issue - either a bad ground, a stator on it's way out, or pinched harness somewhere - could be in bars, tunnel, or main harness. Injector harness tends to rub on heat shield under y-pipe - good place to start looking, look very closely as the wire will be just slightly discolored.

 

[gibsons]

my 07 had a wire rubbed thru on the injector closest to the primary. green wire on top of the rail i believe, caused by the throttle cable. also noticed on my 08 m8 that the spark plug wires on the clutch side are also rubbed thru almost to the wire. just a couple thing to maybe check out.

 

[bdietz]

I am having this problem with mine again does anyone know what is going on
I was told it may be a bad coolant temp sensor shutting off the fuel pump
after pulling out a plug and putting gas in the cylinder it started after a few pulls and ran after that
although it was a bit sputtery at slow trail speed
I already have my throttle safety unplugged as it was causing problems before and haven't got a new one yet

im pretty sure it is fuel related

 

[cnelson6]

Ive been told that the tail light harness on these sleds have a problem with rubbing through and grounding out from time to time and causing a world of problems. Alot of these issure sound like electircal to me so this may be a good place to take a look.

 

[turbofarmer]

exactly same thing was happening to my 09 m8. Ended up being fuel pump.

 

[bdietz]

ok thanks I will talk to my dealer about the pump I am thinking the same thing I found a plug wire rubbed but I still had spark when I was having the problem so Im certain it is fuel related I looked over all the wires up front around and under the aluminum shield and all looks good the tail light has always worked fine