newbie, cr250r x2 owner need top end help 2002

[bburtonsk8r]

whats goin on guys, im usually on honda-tech forum, but need some help with my bikes now... i have a 93 and an 02 cr 250r, just got the 02 for 1650, bike is in really good shape, but was knocking, so i pulled the top end off, the piston has scraping on the front, by the exhaust port, and the slightly on the backside, minor scraping on the cylinder. the guy told me it had a recent topend rebuild, im thinking maybe the wrong size piston or something, what would cause this piston slap? everything looks alright besides this, no rod play up and down, can still see cross hatch on cylinder, piston reads 66.34 on the top of it. i would like to get an oem honda topend kit and rebuild, not quite sure about the bore, and if i have to resleeve or just hone and throw a new piston in... any help is greatly appreciated. thanks braden burton.

[370banshee]

thats a plated cylinder. just hone it and toss in a piston.. the rason for the exhaust side damage is probably a lean oil ratio. a 2 stroke will always tear up the exhaust side before the intake side because the exhaust side is the last thing to be lubricated by the premix.

[clutchcargo]

I have had Honda CR's forever, and they tend to sound like the piston is slapping, especially at idle. Like 370 says: Check your jetting and oil mixtures also.