Take a look at these piston pics

[97GSX]

http://f1.pg.photos.yahoo.com/boomer92
Take a look at these pistons and cylinders and tell me what you think. Before taking the motor apart the compression was good 150 in both cylinders. I removed the head to add an R&D head and this is what I found. The PTO piston with deto, Mag side fine. I just replaced the same piston just a month ago. I noticed some damage to the rave valve and noticed that the rave piston was stripped so the rave would not go up.
Any suggestions would be helpfull.
Thanks CHris

[rotax racing]

that doesn't look like detonation...it looks like debris going through your engine . better do an inventory of engine internals to find out where the stuff came from

[Technical Support]

I would check your crank to make sure there is no bearing damage as well. The damage to the rave valves I do not believe are related to the them not moving easily unless this engine was bored over and the valves were not cut to meet the specified clearance. I would also check your carbs but from what I saw in the pics the engine looks ok

[cerv96xp]

thats what mine looked like when the motor
tide up

[Bill O'Neal]

I think someone left some debris in the cases when he rebuilt it last time.

[97GSX]

When the engine initially failed ,there was alot of shavings in the bottom of the engine. I blew most of it out with a air compressor. I took new pics so you can look closer at the piston and rave. The part of the rave is damaged and where the piston has the most damage is in the same position. I did inventory and all the clips and needle bearings where there(34 of them), the ring pins where there as well. Why would I have to check mt carbs????
Later Chris