piston and cylinder size

[whitewonder66]

i have a stock banshee and the rod bearing when out and blew one piston. the cylinder was in good shape but i think i am still going to bore it out to 65mm. does the piston need to be 65mm or is the cylinder need to be 65mm.

[BigRed350x]

Ummm.... both. Your cylinder bore has to match your piston size. Why are you blowing away almost half your bores though? Most times you can fix minor scratches and crap with like .020 overbore. If you go 65mm you're wasting about half the bores you have without the need. Send your cylinders off to a builder and have them inspect the damages and they can tell you what size piston you need to fix the problem. Generally you would buy the pistons first and have the cylinders bored out to match the pistons, with the appropriate piston/cylinder clearance. But you want 64mm pistons for 64mm cylinders and 65mm pistons for 65mm cylinders, etc.