87 top end rebuild.

[nirvanafan98]

I took top bend off my kx500. 87 model. Used. Doesn't have the electro fusion cylinder in it .some one put a sleeve in it . A magnet will stick to it . Also piston is different that stock . It has a newer style double set of rings . My question is I measured the cylinder with a micrometer. Measured 87.85 mm. Piston measured measured 87.35. The Wiesco position says 2.00 mm I assume that means 2 over stock . That would be 88mm right. Want to do a top end rebuild. Does the cylinder has to bored to 88mm or can I just get a new piston and what size ? Thanks for help.

[dave916]

If your piston says 2.00mm oversize the piston should measure 87.8/87.95mm
 bore should be 88.035/88.10 

A 2.00mm wont  fit in 87.8mm bore
 if the piston says 2.00mm on it sounds like your measuring might not be correct

[nirvanafan98]

OK , thanks. I bought the bike used an 87. Someone put a bore able sleeve in it and the incorrect piston. The new style. Will have to bore cylinder. And rebuild top end. Thanks again.

[dave916]

If is has 2.00mm piston fitted you wont be able to bore cylinder

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