Hey guys. Been along time since i have posted on here....used to be on here daily.
But here is my question.
2004 ds650 had an engine failure back in 05 i believe...... if any of you remember there were certain model numbers mainly 04 ds650s that had premature piston failure due to the rings. Anyways bombardier fixed it under warranty for the most part. Ran good ever since then put many hours on it over the years. Last summer rolled around and i started to have high heat issues no matter what i was doing with it. Checked compression said 90psi, threw some oil in the spark plug hole jumped to 120. GREAT was the first thought in my head. Pulled her apart after leaving it alone in the corner of my garage all winter. What i found was the head seems fine and valves seem fine, top of piston looked fine.....pulled jug off and piston rings all there. Baffled i took the jug outside to the sunlight to look at the nikasil lining to see if there was something i was missing...what i found was two fairly deep about 2" long grooves wore into the wall.....would this cause my compression to go that bad? i mean ive seen allot of cylinder walls allot worse than this and they are fine there is only two little grooves i can feel the indent with the end of my finger. What i figured i was going to find was broken rings and a F^&*%D up cylinder wall then my plans were to send it away to be re nikasil lined and throw a 11.5-1 CP piston in it and be done. What do you guys figure? Should i be looking somewhere else maybe at the head for my compression issues?????

Thanks!!!!

 

I would say you cylinder is probably done. They are never the same once they are bored or re-coated. Best thing to do now is buy a new cylinder from Eric Oldham. He has a re-designed cylinder that will take your displacement to 730cc.