I was out trail riding o my 97 Warrior today and it was running great but all of a sudden it just quit. I got it back home and checked for spark and there was spark, I also checked the timing chain and that was fine too. I then checked for compression and there is zero. I dont understand how I loss compression all of a sudden like that, the machine is in very good condition and it was running strong just prior to losing compression. Does anyone have any ideas, rings? valves? or maybe the headgasket? Where should I start?

 

Could be a broken piston ring, or it leaned out and you burnt a hole in the piston. Pull the valve covers off and see if the valves look ok from that angle. Good luck

 

It actually read (0)? if so thats wacked... probally your tool is broken? You would think even without rings or a headgasket just the air from turning it over would be a couple lbs?..

 

My friends did the same thing. It was his compression release on the camshaft was stuck.

 

Stuck compression release or stuck (as in, burned) valve will cause immediate zero compression.

Most other compression problems (rings, eroded valve faces/seats, etc.) cause LOW compression, noticed in gradual advancement over a period of time.

Diogenes

 

You were exactly right, it was a stuck exhaust valve. I guess I'll be off the trails for a couple of weeks till I get my head back from the shop. Thanks for everyones help.