ATC 300R Specs....Need help from you big bore foolers!

[Super350]

I was wondering if anybody knows the specs for the 300R kits. Im talking stock bore. Im getting a cylinder cleaned up/honed and need some numbers for the machinist

I need the piston clearance and if there is any special spot you are supposed to measure it from

Any other info you guys that have done this think I may need im all ears


Also, the rings are just regular cast , not plated or anything, correct? thanks

[atc300r]

300r stock bore is 76 mill. Yes on cast rings..003 pston to cylinder clearance.

[Super350]

I love this site, thanks atc300r! :beer

[Super350]

.003 inches im assuming right? and is this the service limit or standard? also just measure this from any point on the cylinder?

I was looking at the 81-84 250r specs per the manual and the cylinder to piston standard clearance is .002 to .004 and service limit is .006 inches. Whats with the much tighter spec on the 300 cylinders? or am I confused?

thanks

[Flossyb20]

Clearance specs are the same as the stock 250r...shoot for 003, that way you won't freeze up with too little clearance or have a short life with too much... .006 is the service limit.

[Super350]

awesome thanks Floss!