I have a 99 CR250 that I've had for about 8 months. It's got about 40 hours on the Wiseco piston that's in it now. I had it out last week, and I noticed that it had significantly less compression and had stalling/restarting issues when hot. I pulled the head today, and noticed smashed debris on the top of the piston and a long scratch on the right side of the sleeve. I'm guessing it's going to take both a new piston and a replating at the least. Before I tear the cylinder off, I have a few questions:
The head has impressions/roughness in the inner ring (squish band) from the debris smashing between the piston and head. The outer ring where it mates against the gasket is fine. Can I resurface the inner ring, and how would I go about doing it, or will I need a new head?
I'm not sure what caused the debris, or if it is still in my lower end? Am I going to have to do a full tear down, or is there an easy way to clean out small debris from the lower end?
Thanks,
Craig
The head has impressions/roughness in the inner ring (squish band) from the debris smashing between the piston and head. The outer ring where it mates against the gasket is fine. Can I resurface the inner ring, and how would I go about doing it, or will I need a new head?
I'm not sure what caused the debris, or if it is still in my lower end? Am I going to have to do a full tear down, or is there an easy way to clean out small debris from the lower end?
Thanks,
Craig
