:hallo1: I don't get it .The sled was running fine ,and then sputtered.
I was travelling at around 35 kmh. The sled went down to one cylinder so i hurried to stop ,and shut it off . Lots of compression in Pto. side cylinder, dead cease in Mag. side. What the hell can cause such an in balance all of a sudden . Temp. gauge was 65'deg. sled has lots of oil. I had no warning lights come on. Is it possible to have temp. gauge register wrong temp. or wouldn't it just not work? :bash:

So you carry a compression tester with you when you ride? Are you sure you lost compression? How did the plugs look?

Was not far from home luckily ,but yes i do on longer rides have one in duffle bag. 150psi in pto side. no comp. in mag side. Pto side plug was wet . Mag side showed normal wear greying with no bubbles or build up .

What kind of mileage on the sled? Sounds like maybe a head gasket went. When you pull it apart let us know what you find.

One time I was out sledding with my buddies and the same thing happend to him , and what the problem was is one of the oil injecters or both I can't remember stopped working , it gave him no warning at all. Did you check them ? Let us know. good luck ! :blush:

Originally posted by ashes@Jan 17 2005, 11:25 PM
One time I was out sledding with my buddies and the same thing happend to him , and what the problem was is one of the oil injecters or both I can't remember stopped working , it gave him no warning at all. Did you check them ? Let us know. good luck !* * * :blush:
390426

No oil would most likely cause it to seize if i'm not mistaken. Iv had extremely scored up pistons that still had decent compresion. Its odd like underdog said that all of a sudden he had no compresion at all. Not to rule anything out, just my 2 cents.

Is the zero compression side moving the piston? Stick a screwdriver in the sparkplug hole and pull it over slowly and see if the piston is moving at all. Sounds like you had a rod or piston pin break, or you blew a hole in the piston, or maybe the crankshaft busted in half. Or like stated, a head gasket blown, but usually that doesn't cause a full ZERO on the compression guage. Highly doubtful it's a lubrication issue. You gotta at least pull the heads and take a look-see to figure this one out, probably pull the cylinders. If it's a hole in the piston, might be lean burn-down. Any of the others, it's just fatigue/mechanical failure....happens to the best of us.

I guess if it was a head gasket there would most likely be traces of coolant? Either internally in the cylinder or eternally leaking, :sleeping: i think i was sleeping on that one. I'm guessing if it was a rod or a pin letting go, it would have made a heck of a racket?

It doesnt take much to go down to Zero compression. I have experienced it on same motor. Only this was a brand new 99 583. Bought brand new for the wife for our annual week long tour. Was running great. Actually we were doing just a little racing, playing side by side when "It just quit". Zero compression mag side. What happened? A small sliver of plastic...probably came off the in line filters they used to put in the inlet of the carbs. Sliver got lodged in main jet, leaned the cylinder out, quickly burnt a whole down the side and the rest is history. I would be taking a close look at carbs while it is apart.