Race Ported Zenoah 27.2cc 4 Bolt Top End

This is a brand new race ported 27.2cc 4 bolt top end. This kit requires a 2mm crank shaft. To start we machined the combustion chamber for the longer stroke with out stacking base gasket. This kit comes with a hand ported 34mm cylinder cut for a 2mm stroker, piston, ring, wrist pin, c-clips, spark plug, and base gasket. The following machining and port work has been done:

1. Machine combustion chamber for 2mm stroke

2. Resurface all ports for better gas/air mixture

3. Modify transfer ports for better flow

4. Raise/enlarge/reshape exahsut port

5. Rebevel all porting and factory bevels to prevent damage to the piston