Recommendation?

[corypro]

Well, I'm about to order some pistons and a top end gasket kit but I've got a question. After inspecting the heads, it looks like the pistons were just replaced and the engine wasn't broken in. The pistons were 64.75mm and one had no wear whatsoever. Would you recommend boring to 65 or would you think it's okay to stick with 64.7mm? If I go over once more, I've been quoted $160 for the bore. IMO, I don't really see the need but I wanted to ask for your opinion.

 

Thanks

[AKheathen]

um, if it's not broken in yet, then why are you doing it? to answer all your questions, have them mic'd out to see what size it can take, and what clearance it has with the pistons. possible ring job/hone?

[corypro]

um, if it's not broken in yet, then why are you doing it? to answer all your questions, have them mic'd out to see what size it can take, and what clearance it has with the pistons. possible ring job/hone?

 

I'm replacing it because a piston is shot. It completely disintegrated. I mic'd the one piston and it was exactly 64.75mm and was in impecable condition which is why im thinking the motor wasn't broken in yet when a piston was blown

[AKheathen]

oh, do a leak-down test when you are done, and check for plugged jets/passages, or other fuel issues in that carb. still you will need at least a hone. have the cylinders mic'd with bore gauges to see if you need to bore to the next size, then have the new pistons there to match clearance to the exact pistons.