I am working on a buddies 1991 indy 400 that has no power and seems to load up and foul plugs at cruising speed. He just bought the sled for his kids and it has never run right for him. I own cats and ski-doo's and do not have any information on this sled. What I need is stock carb specifications and compression readings.

The parts currently in the carbs are:

30 pilots
210 mains
1-1/2 air screw settings
2.0 slide cutaway
needle in middle position
unknown needle jet and jet needle (I need to check)

compression is 110 PSI both cylinders

The carbs are clean and do not appear to be causing the problem unless the parts I listed are not correct for this engine. I am leaning towards worn out rings and pistons but I need to do some more investigating before I come to a final conclusion. The engine seams to have alot of reversion (maybe poor ring seal) in the intake track if I idle the sled with no air box it is spitting back a fog of fuel.

Thanks

I am working on a buddies 1991 indy 400 that has no power and seems to load up and foul plugs at cruising speed. He just bought the sled for his kids and it has never run right for him. I own cats and ski-doo's and do not have any information on this sled. What I need is stock carb specifications and compression readings.

The parts currently in the carbs are:

30 pilots
210 mains
1-1/2 air screw settings
2.0 slide cutaway
needle in middle position
unknown needle jet and jet needle (I need to check)

compression is 110 PSI both cylinders

The carbs are clean and do not appear to be causing the problem unless the parts I listed are not correct for this engine. I am leaning towards worn out rings and pistons but I need to do some more investigating before I come to a final conclusion. The engine seams to have alot of reversion (maybe poor ring seal) in the intake track if I idle the sled with no air box it is spitting back a fog of fuel.

Thanks
[/b]

i have the exact same sled and i ,lov it .sounds like carb problems.you say it fouls plugs when cruising and is pushing a fog of fuel out through the carbs.so i figure it is most likely flooding.110 compression isnt the best but in my experience anything over 100 is usally pretty good and with both cylinders being the same i would not worry about that.also maybe check the plugs maybe wrong type i run number 9 plugs.the screw ajustments are correct.also check the choke cables they should only have one eigth inch play with choke in off position.i dont have the exact figure for the carb specs but i would bet money it is flooding.you say he bought it for the kids i wonder if someone has been monkeying with the carbs before he bought it but anyways pickup a clymer manual all you need should be there if i had one i would give you all the info you need but maybe someone else here may have it for you hope this helps