Ok so here's the deal I posted before bout' the sled bogging down. Found out it wasn't the clutch or belt it was fouling a plug on the fan side

Changed the belt anyways and plug (8's which are proper and gapped) got it running good again

So two days ago I go for about an hour ride no problems. Today I start it up, let it warm up and take off. Get about 1/2 mile and foul the fan plug again. walk home grab 2 more plugs put them in and foul it again. Same tank of gas as two days ago(40:1)

Took the good plug out and put it in the fan side and fouled instantly

Any ideas

I thought I should add again it's jetted ok plug are brown usually carb was cleaned new fuel line new belt clutch cleaned etc etc

oh yeah 82 mirage 2 fan cooled single mikuni carb 377 rotax

Also I put a new(used but good) track on and I think it's a little tight any info?
New slides shock greased everything etc man I put so much time and money into this thing this season it's just pissing me off

Have you tried hotte plugs in that side? If it is not that then maybe the compression on that one side is gone. CHeck it by taking the plug out and Either get a compression tester or put ur thumb over it and pull it over. If it pops off with great force then it is good.

compression is fine. My buddy told me to put in some br9's the ex iradium's specifically does this sound like a good idea to anybody? according to him it would be rather hard to foul them

I bought some iridium br8eix's i'll let you guys know how they work out

Same thing although not as bad? Any suggestions. What would cause this coil?cdi?

I did the plugs first since they are the cheapest thing to change what would be next or how should I test. I don't want to change cdi or coil and find out that wasn't the problem

spending money for no reason sucks lol

Do you have spark on that cylinder. Maybe if the spark is ok, your float is sticking or there could be ice in that carb. Does it have dual or single carbs? If the spark is good. I would pull the carb and go throught it.

I had the same problem with my 96 Formula Z 583, it turned out to be my fuel pump, I cleaned my carbs, replaced the needle and seat on them both but that didn't fix the problem.
I asked the local Skidoo expert what could be causing the problem and he asked if it was the same carb that was flooding and fouling that side plug, it was, he said it's the fuel pump.
It's not hard to check.

Kevin

single mikuni carb. so that theory kinda doesn't apply since the other side is getting gas. Carb has been cleaned anyways and fuel pump is fine. I'm really stumped

I just took it out again and set the mixture screw to about 1 1/2 turns out but sometimes it bog(just barely) on take off

The throttle response seem to be lagging a bit

I was told to look where the fuel pump goes into the engine (right side or left side) this might not be the case with your sled but it cant hurt to look. Mine fouled that side always.

Kevin

This might sound kinda stupid, but this is my first year riding. How do you know when you foul a plug while riding? I assume I will feel a loss in power or it will seem like its missing?

In my case when I foul a plug then the engine runs on only one cylinder so what happens is a major bog and lack of power and the sled has great dificulty moving

Anyways the fuel pump goes into the left side of the carb but the carb goes into the engine in a Y manifold and the other side never fouls

Gaskets are new compression is good plugs are new (iridium) carb is clean fuel lines are new fuel is good new belts new track greased undercarriage etc etc so I guess it would be a coil or cdi problem?

How would I check either of these?Does anybody have a testing method for the coil or cdi?

Well, first, how is the plug wire?

new plug wires last winter(ngk). I would say they are in pretty good shape