This is the long-anticipated 4-bolt Zenoah 36mm 29cc bigbore kit! This kit will fit Zenoah G240RC/G270RC engines, or any engine running the 4-bolt Zenoah cases. This includes the parts shown (piston, cylinder, ring, spark plug, base gasket, c-clips, pin). 

 

These big-bore kits have been race ported by ESP - intake, exhaust, and transfer ports have been enlarged/reshaped for more fuel/air flow.  This cylinder kit can be used with a standard or +1mm stroke crankshaft.  To use this cyliner for a 30.5cc engine (+2mm stroke crankshaft), you will have to use a .040" copper head gasket to allow for the proper squish clearance at the top of the cylinder.