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Discussion Starter · #1 ·
[:(]After thinking (my mistake) that it was a carb problem (carb backfire) thus probably a fuel problem (lean mixture)(lack of power)(fuel pump) decided to check compression before doing more than cleaning carb. "0" on one side. So my question is "how well will a snowmobile run on one cylinder?
a)Idle but not rev up.
b)Rev up and engage clutch.
c)Rev up but not move.
d) Move along at a crawl.
e)Get up to low speed.
And as many of us would wish
f)Drive like nothing is wrong.
 

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Are you posting this from the top of a mountain,
and the only way down is on this pooched sled?

Fix it now before you turn a minor piston replacement into a full engine rebuild.

If you are getting 0 compression there is only 2 possibilities:

1. You have a pooched piston.

2. You are sticking the tester in the wrong hole (note: you do not need to remove your pants to do a compression check)
 

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It will get up, and move to a low speed. You half approximately half the HP, when your other piston is free-wheeling.
 

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D, if it will start. ZERO compression? You must be missing alot of piston.
 

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It will start and run. Ever pulled one spark plug, and let your motor run? runs alot rougher, wayy less power, but still runs OK.
 

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wow 0 compression!? How would you blow it that bad?
 

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i saw 0 this winter :(
 

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Like Bob said sounds like a hole in the top of the piston. 500fasEnuf now you tell me I don't have to remove my pants to do a compression test. Riley
 

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When I have been on a sled that is only running on one cylinder the results have really varied from not even starting to being able to go like half the normal speed. I think it depends on the sled??
 

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Originally posted by Riley
[br]500fasEnuf now you tell me I don't have to remove my pants to do a compression test. Riley
Riley,
You don't have to remove your pants to do a compression test, but what ever you do in your shop is your business.

Now, let me guess what your next reply will be....

"Come here and say that...."
 

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0 PSI?

A few years back I rebuilt an '82 Ski-doo Alpine (640 twin) and with a 1/4"+ hole burnt through the top of one piston, that cylinder still regietered 20-30 psi!
 

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Discussion Starter · #15 ·
[xx(]Pulled off the heads today, one hole along one side that has exposed the rings. The rings are free standing in that area, surprised they didn't crack. Another smaller hole 30 degrees off that, but on top of the piston a dished out area at least 1/4 inch deep, and at least 1 and 1/2 inches wide right under sparp plug. Any idea what could be the cause of this? Got the snowmobile used so don't know the history. It is a liquid cooled(1996) 494 ski-doo. There is damage to the cylinder walls. (important) Does any one know if there is a sleeve in this cylinder, does a machine shop have to press this in if available. And if possible does anyone know of a machine shop that can do this in western Canada. There no facilities in the community that I live in the North West Territories that could do this. Thanks Cam
 
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