2008 keeps fouling right side plug

coryf89 · Apr 29, 2017

what is the cause of this?

bought sled used. 2500 miles. fouled right plug first ride.

right piston was realllll bad, so we re did top end. $400 still ran bad.

dealership scanned it, had a few electrical codes, said stator is bad. 100%.

we replaced stator...$200. same thing! ran rough.

took it to a local pro. he said the wiring harness is bad. replaced that. $800, t rode for 5 miles.. same thing, right plug died.

please help!!! what could it be.

BBP · Apr 29, 2017

DPM, fuel pump & spark plug boot would be the 1st things I would check.

BBP · Apr 29, 2017

I would also confirm that you have good spark & check the compression. Might also be a broken reed.

Skidoox · Apr 29, 2017

What jet are you running?
What altitude are running the sled at?

coryf89 · Apr 30, 2017

damnit, we had the jets out but I cant remember the numbers. we are at 1000-1500M.

compression seems fine via the pull start. brand new pistons.

reeds seemed fine via visual check.. not sure if they should be checked with a magnifying glass and feelers guages sorta thing.

spark seemed fine the one time we pulled plug, stuck it in the boot, grounded it, and pulled sled over.

spark plug boot and coil are the next things to guess/throw money at!!!

appreciate the advice/ tips... anything helps. keep the suggestions coming please and thanks.

bought the sled, used it once..this sucks!!!

Betterview · Apr 30, 2017

When a sled is used I would not trust the number on a jet is true to the size. It is very easy to enlarge the orifice to compensate for low compression or an air leak. Put in a new jet the same size the other carb has and go looking for air leaks, carb boot, crank case seam, base gasket, including the seal behind the mag.

eddy · Apr 30, 2017

Jets

Agreed on the used machine and jetting. Replace the pilot and main jets on both sides with stock. That stock machine with DPM and stock jetting runs perfect at that elevation.

The ignition is common to both sides, so other than a plug wire/cap, IMHO you are chasing a problem most likely not in the ignition.

Skidoox · Apr 30, 2017

I would test the DPM.
Or swap the DPM from a working sled.

coryf89 · Apr 30, 2017

good answers guys. DPM seems to be a common answer..

ill order new jets and throw them in.

the mag side seal isnt perfect TBH... when replacing the stator, we did see isoflex that had leaked out to the stator case and pullstart assembly.

eddy · May 1, 2017

Right Side

"the mag side seal isnt perfect TBH... when replacing the stator, we did see isoflex that had leaked out to the stator case and pullstart assembly."

That can be the cause of a lean cylinder and the root of all evil and much grief! Time for a leak down test.

winter brew · May 1, 2017

Check the DPM solenoid. It's simple with a 9v battery and a paperclip to see if it clicks. It is common for them to stick which will cause a rich condition...I would think both sides would be effected but it's quick and easy to check and cross off the list of possibilities.
If it sticks, just take a apart and clean with WD-40, there was a bulletin from BRP on this back in '08-'09.

coryf89 · May 1, 2017

hmmm.. is it electrical or from the leaking magneto side seal?? hard to tell. maybe itll be a bottom end tear down this summer

now that you mention it...I believe we did take the DPM apart, and push the little plunger back and forth a few times, it didnt seem to be stuck.

winter brew · May 2, 2017

coryf89 said:
hmmm.. is it electrical or from the leaking magneto side seal?? hard to tell. maybe itll be a bottom end tear down this summer

now that you mention it...I believe we did take the DPM apart, and push the little plunger back and forth a few times, it didnt seem to be stuck.

Make sure it clicks with 9V battery to the plug and that the 2 0-rings are in place.

Rick E · May 2, 2017

coryf89 said:
what is the cause of this?

bought sled used. 2500 miles. fouled right plug first ride.

right piston was realllll bad, so we re did top end. $400 still ran bad.

dealership scanned it, had a few electrical codes, said stator is bad. 100%.

we replaced stator...$200. same thing! ran rough.

took it to a local pro. he said the wiring harness is bad. replaced that. $800, t rode for 5 miles.. same thing, right plug died.

please help!!! what could it be.

I am fairly new at doing Skidoo mechanical work and I am very new to this forum. However, I am not new as a mechanic. I began working as a mechanic back in the late 60s, wrapping up the more recent 24 years or so doing Volvo Penta repair.

Although this may not always work, here is my suggestion that may help prevent paying for work that was un-fruitful:

In the future, when you have your snowmobile, car, truck, lawn mower, tracter, etc worked on, first ask for diagnostics. Be willing to pay for the diagnostics if need be.
Then ask for a work scope "quote" (not an estimate). Make sure that the work scope "quote" references the diagnostics.

Authorize the work ONLY if the verbiage references the diagnostics as having isolated the issue, and that the work scope will correct the problem as per their diagnostics!

We've all seen this whereby people have paid for work that did not correct the issue. In my opinion, there is no need to pay for work that does not correct the problem....... especially after proper diagnostics!

Rick E.

.

coryf89 · May 3, 2017

very good post.

the top end was my doing... the one piston was destroyed. other piston was a new wiseco. he needed one anyways... was hoping it woulda fixed the problem. it didnt.

the stator diagnosis came from the dealership. 100% they said. 900$ fix. they scanned it, tested it, poked and prodded it for two days. I ended up ordering a used stator off ebay for $100. installed it.... didnt work. even worse now, we had no headlights.

took it to a proper local backyard mechanic.. builds drag sleds, its all he does is sleds, had a big new shop with 10 sleds in it being worked on. he said its for sure the wiring harness after playing with it for a week. $900 later, it ran great for 5 miles. pretty sure it ran great because there was a new plug, otherwise exact same as before!! SO, with that being said... what would you guys do about that? harness was like $350 and 8 hours labor.

were gonna try the cheap things first... coil, plug wires, etc.. and go from there!! dont wanna jump into a bottom end rebuild without checking the easy things first.

BUT, the mag seal does need to be adressed, I totally agree... try convincing the owner that!!!! good luck.

thanks for the answers guys.

Rick E · May 3, 2017

coryf89 said:
.................... SO, with that being said... what would you guys do about that?

Since the work scope did NOT correct the problem, I would have been inclined to asked for reimbursement!

Rick

lynxmann · May 4, 2017

That the mag seal have let out some grease does not mean it is defective actually this is quite common. When the crank bearings is packed with grease they sometimes get a little to much in there so when the engine gets hot the grease expands and pushes threw the seal. I would not worry about this, the inner bearing at each end of the crank is also sealed at one side so even if the mag seal is bad it most likely is not the reason for your problem.

FEZ · May 9, 2017

X2 on the seal, After rebuilding a couple hundred 800R's over the years, most weep some isoflex.

Now I am gonna bet you have a bad O-ring on the needle/seat on the side that is fouling. These little buggers get hard over time and do fail.

Open up the carbs. Remove the 2 Phillips screws holding the plastic seat in place, remove it and you will see the O-rings. Replace them and let us know.

The DPM, if bad, will cause a major rich condition beyond 1/2 throttle but will run fine below.

coryf89 · May 10, 2017

so is that an OEM part we can order from a microfiche? http://www.rifleperformance.com/OEM...ummit_X_800R,_2008/02-_Carburetor/46683/46691

new o rings in the carb, new coils.. what else for small parts?

76 and 77 here: http://www.rifleperformance.com/OEM...008/01-_Engine_And_Engine_Support/46683/46688

BBP · May 12, 2017

Check your fuel pump. If fuel is getting into the impulse line, it will dump into the mag side crankcase.

2008 keeps fouling right side plug

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