01 CR250 Cylinder Help with image

Hey Gang,

Just purchased an 01 CR250, the air filter was trashed, however the bike ran fine. Pulled the carb and of course it has some trash in it, so I pulled the cylinder and it is within service limits, but it has a slight bump on it. Thinking I probably need to have it honed and coated. The piston was well under service limits 66.00, service limits are 66.28.

You can see the spot on the cylinder in the picture. I'm betting the piston was slapping that spot due to it be worn. Whats your thoughts?




id get it re-plated.. who knows if its out of shape plus new rings will eat right threw the aluminum wall

Whenever you replace a piston you should run a bead hone through it. I can't really tell by your picture if it is a bump or just wear in the metal but measure that up and see if it it within spec. Use a T handle micrometer

You've worn through the plating. That light color by the arrow & above the exhaust port is aluminum. It needs to be re-plated.

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