Snowmobile Fanatics banner

1 - 20 of 38 Posts

·
Registered
Joined
·
36 Posts
Discussion Starter #1
I have a 1995 XLT SP 600. Ijust cleaned out carbs and synched them, all new plugs, gas, fuel lines. The problem is when idling idle fluctuates. When you punch it the sled bogs down and backfires then it screams. Sometimes it doesnt do that at all. I put it up on a stand with the hood open and i think the popping is coming from the clutch side cylinder. All the plugs look fine and compression is 123 on all three cylinders. Could this be a blown crank seal. Please help me out. I am stumped.
 

·
Registered
Joined
·
56 Posts
easy way to check crank seal take some brake/carb cleaner and while the sled is running spray the seal if the sled revs up the seal is shot. but it sounds like it might be getting to much fuel. does it still do it if you just ease into the throttle.
 

·
Registered
Joined
·
36 Posts
Discussion Starter #4
carbs are set up exactly how slp recommends with pipes. 160 main jet, needle dropped one clip, 30 pilot jet, oil injection advanced 2mm
 

·
Registered
Joined
·
56 Posts
u could try dropping a size on the pilot unless your already at a light brown when you read the plug
 

·
Registered
Joined
·
36 Posts
Discussion Starter #9
the plugs look great. Just where they should be. I think the only thing left is a crank seal. Sled ran great last year with this setup. Never had a problem
 

·
Registered
Joined
·
56 Posts
i still think its fuel. ive never heard of somthing backfiring because it was to lean and also if the crank seal is bad thats what will happen it will suck in air.
 

·
Registered
Joined
·
56 Posts
no if it's bad it will suck air forcing at least the pto side cylinder to run lean and ive never heard an engine pop because it was too lean
 

·
Registered
Joined
·
36 Posts
Discussion Starter #15
it is only that one cylinder popping. I dont see how carb setup would be wrong in one cylinder. There r all the same. Air fuel screw is out 1 turn. should i open it up more
 

·
Registered
Joined
·
56 Posts
that might work but the only other way to reduce fuel is to reduce jet size. does the engine have reeds?
 
1 - 20 of 38 Posts
Top