Motorcycle Repair: to bore or not to bore?, maximum compression, measurment

Question
89 honda cr80r dirtbike 2 stroke need to be rebuild on top end. cylinder has slight to moderate groove wore in it. where the ring broke. Should I have it bored and put sleeve in it or should I just chance it rebuild it and hope for the best? Dont want to put a lot of money into it.

Answer
Rodney,
 Typically you will have 3 or 4 overbore sizes above the factory original bore on the same sleeve.  My suggestion, have a bike shop rebore the cylinder to the next size and install the matching oversized piston and ring set(Be sure to give the shop the next size piston and rings you've purchased ahead of time, just for safe measure. The bore measurment is preportional to the outside diameter measuement of the piston at the skirt.)  A rebore on one cylinder should not run you more than $40.  You can either use an aftermarket "Wiesco" piston and rings or the OEM Honda piston and rings.  

Essentially, $40 to ensure maximum compression, you'll be purchasing the piston and rings in either case.

Hope this helps,
Mike