Texas-1-lunger wrote on 10/26/09 at 12:30:28:So I guess its time to bore it I just need to know what part # for the oversize piston?
And does anyone have a Head layin around.
Only when I'm sleeping...
Look on fleabay, there's a wisco piston kit for a dr650/ls600/650 (just look for dr650) that's 1 to 2 mm oversided. These are high compression pistons for us. The stock dr650 is 1 mm oversize for us. Wiseco has there data wrong for the ls650. Getting them to correct it will take a "visit" to convince them they are wrong.
You might concider getting Boretech to bore it and nicklesil it.
I've heard of a few valves letting go, but not many. Any chance it was the cam chain? If not, I'm going to assume the valve got stuck and the piston smacked it. I think it's more likely than the keepers popping out.