Rebuilt last year with all new Yamaha cylinders, pistons, rings, and bearings.
One crank seal had blown.
No other damage to bottom end.
Stuck ring on one side.
Other side was running a nice 155 psi.
Pieces were all blown out and it was still running when taken apart but kept fouling the plug on one side. lol
Came out of my half brothers sled.
I think he may have been drinking while riding this unit!
Says he never heard any noise.
. he didnt hear anything 
ray charles would of heard that
