Top End Rebuilt for a Zenoah Strato/Geo 25.4 cc

[GoldenEagleChris]

Hey guys, I am doing a cylinder replacement and want to know your opinons.

If I only have enough money for a new cylinder...can I get away with changing the piston rings only and reuse the old piston...it looks fine....

...so should I do it or save up for the new piston too?

My racing goped buddy said new rings should do the trick....


Also....are there any instructions on how to remove/replace piston rings?

The last time i did it was a year or two ago and I remember having a hard time and even breaking one ring...any tips?

 

[GearNut]

While it is not recommended, you can get away with using the old piston if the new cylinder bore size is identical to the old cylinder bore size. If we are talking about a Nikasil plated bore your chances are even better. Cast iron bores should be measured to ensure proper piston to cylinder clearances. They are typically finish honed to a custom size dependent on the piston size. Either way you choose to go, research the recommended clearance for your engine and definitely check it before assembly.

This may also help you out in determining of the piston is worthy of re-using:
http://www.smellofdeath.com/lloydy/piston_diag_guide.htm