M8 thats stalls out continuously.

[Mark P]

I could use some help here in getting some ideas as to what is wrong with my 2007 M8 with about 2000 miles.
The sled dies out once it has warmed up after ride it a bit hard or after about 15 seconds of a wide open pull. usually it does it when I let off a bit on the throttle and then it will sputter out like it out of fuel. Once in a while I can save it for dieing completely. It fires up up first pull every time after. I've looked twice for wires that have shorted including under the fuel tank, disconnected every electrical item i could isolate to try to find it. The dealer here said timing sensor and they changed one, I tryed changing the other. tested out the water temp sensor, EGT sensor, and stator. Whats left? ECU, trottle runaway switch, and ignition coils? Any suggestions or ideas would be helpfull as I feel like lighting it on fire and sending it on it way right about now.

Thanks

 

[SLEDIOT]

First of all, welcome to SW brutha!! Now list what Mods youve got on that vintage m8?

 

[Mark P]

Thanks for the hello.
Just an SLP pipe and can plus a 2010, 162 skid. all else is stock. My buddy and I spent about 2 days going over this sled and he bleeds cat but is also stumped.

 

[SLEDIOT]

HMMMMMMMMM. Ok wide open for 15 seconds everything gets hot and expands. I wonder if maybe you have some piston issues. Rings getting pinched in your pistons and a partial clamp of your motor. Also possible frayed throttle cable which will set off the broken throttle switch.

 

[ACMtnCat]

Replace spark plug wires and caps.

 

[Mark P]

Your thinkin in the dirrection I was starting to go with the heat from the motor but I was not sure at what to look at. That cable looked fine and it runs great as long my thumb is on a friggin diet, that never lasts long. Once it gets hot it dies, the weird thing is that it will start again right away, maybe 2 seconds cool down time but you would think that
the residual heat would heat the motor more as the coolant stops when the motor does. ???????? and then some more????

 

[Mark P]

Plugs, wires and caps were done. thx.

 

[SLEDIOT]

Replace spark plug wires and caps.

Good Call. 2000 miles do a refresh on everything. Plugs, reeds, pistons, clutching springs, diamond drive oil and bearings, throttle cable, ignition switch, coils, air temp sensor, donuts on pipe (both ends) etc

 

[Mark P]

The air temp sensor and the coils are the only electrical items that haven't been tested or changed out. Could it really be the rings if it fires up again right away? DD fluids are done every season. Clutch was done at 1500 miles.

 

[SLEDIOT]

POSSIBLE WATER PUMP THAT SETS OFF THE TEMP SENSOR? COOLANT TEMP SENSOR? ANOTHER THING TO CHECK IS THAT YOU ARE LOSING PRESSURE ON YOUR COOLANT SYSTEM. DHOULS BE LIKE 1315LS I THINK. IF THE CAP ISNT MAKING THE SEAL AND YOU LOSE PRESSURE DOWN SHE GOES. MY M7 DID THIS. POSSIBLE COOLANT LINE RUPTURE?

 

[Mark P]

I have checked the temp sensor as I plugged another one in and that is a no go, I am not losing any coolant, the water pump I need to pull apart to check. Maybe some of the fins on the water pump are damaged/missing and the flow is not enough causing the piston/rings to get a bit tight for a sec? I've had no warning lights for any of this stuff at any time and the timing code was the only thing that came up.

 

[dhdey]

this might be way out there, but did you check the primary make sure its moving properly cause i've seen them bind on skidoo's and stall the engine out.

btw did you just buy this one or had it for sale just a little while ago?

 

[fasta76]

Sounds like a fuel pump issue. Might not be able to keep up at WOT then runs out of fuel. I would do a pressure test and see if its low. also check the pickups in the tank to make sure they are in the right place.

 

[m8magicandmystery]

any chance you can throw a stock can on it for a test..??

 

[CB.8]

Try the stator.

 

[snopro176]

i have a 09 m10 and mine acts kinda similar sometimes. Yesterday i fired it up and let it idle,it ran rough immediately,tried to give it throttle,just bogged then died. Fired it up right after and it ran clean the rest of the time. Its done that on the trail a couple times as well?

 

[Team Pigeon]

Did you ever mess with the throttle cable? Adjust or tighten it up? Check to see if the lock nuts come loose?
If you don't have enough throttle free play, it'll act up when you're at low rpm when the bars shake.

You need about a credit card thickness worth of gap in there between the little nubs on your flipper and the block.
Lube up that cable too.
You can also test the throttle safety switch by having your sled up on a track stand, hold the flipper back from activating the tss, then give it a little gas. sled should die.

Just ideas, electrical sh it can stump ya

 

[mutti_wilson]

Had a similar problem on my 07 M8. Check the plugs and see what they look like. Mine was super lean and it turned out to be a bad CCU that smoked my ECU. Replaced both and it's running great.

 

[911]

I am having the same issues with my sled, Disconnected the tss,replaced TPS ,replaced Stator and still having the same issue.I am looking into the boondocker box to see if that is the problem.

 

[Mark P]

Stator has been checked, I will look at the trottle cable and switch tomorrow. I'm also thinking wiring harness because when things heat up the resistance goes up and gremlins appear.