300ex rebuild??

[250xrida1290]

Hey guys got a question on rebuilding my 300ex .got this quad used and smokes like crazy and spits oil out the exhaust. I'm thinking rings are shot so I went and ordered a std wisco piston its 11:1 and also says. Clear:0.0020(0.51mm now my question is will this piston work with the stock cylinder? I was gona get it honed also to clean up the cylinder. Is the clear number how much bigger it is? New to rebuilding this will be my first one and I do have a manual best thing invented haha.

Thx for any help guys

[smr]

not looking at it I'm gonna guess it's 20 thousands oversize. It will work with the stock cylinder but you will have to have it bored.

[250xrida1290]

But when I ordered the piston it was a std size piston? Is there a way to verify the new piston and know for sure if I have to bore it bigger.

[jay80]

Any machine shop can measure the cylinder to find out what size it is. Ive always taken the cylinder to the shop and let them bore and order a piston to fit.

[Threewits]

I'm not the brightest crayon in the box, but wouldn't that number indicate .002 clearance between the piston and cylinder wall for expansion?