Yup, the machine shop will be glad to measure it for you. They have the special tools needed to get an accurate reading. I will say that if the bore appears to need a honing, it may be a good idea to just go ahead and punch it out one oversize. That's up to you. A slight overbore won't cause any reliability problems. By doing the top end this way, you'll be sure to have a properly-fitting piston when all's said and done.[/QUOTe
ok the machine shop gave me a very good deal for $100.00.i got the cylinder honed and repainted,they cleaned the ports, and repainted the cylinder head.and fixed the threads.so one more quick question im keeping the old piston and rings because i dont have money to buy new ones.so will i need to break in the cylinder or can i go balls to the walls on my first ride?
No new rings?! Yeah, I understand that money's tight, but having the cylinder honed without putting in at least new piston rings is kinda like detailing your bike, only to go mudding afterwards. It defeats the purpose. :-/
To answer your question, you should take it easy on any cylinder that has had machine work done to it. The piston rings, whether you replace them or not, need time to re-seat themselves into the newly-finished bore. I'm just surprised that new rings aren't going to be installed. Seeing as how the cross-hatch marks were already worn-off before honing, the original piston rings have also been eroded. They won't seat right or seal well if re-used.
To put it in perspective, I have a similar issue with my Banshee. The previous owner took a shortcut while doing a new top end. It ran for about 8 hours before losing compression AGAIN! Dammit! I'm now in the process of doing ANOTHER top end, all because somebody tried to save a buck on cylinder work 8 running hours ago. No offense. Just my .02, 'cause I HATE tearing an engine down twice, to fix a problem that could have been avoided in the first place.