This kit is the complete kit to convert your stock motor into a powerful open class 108cc engine (much more powerful than the common Chinese 107 and 125cc engines). Also - this crank was made specifically for the newer engines and thus - you will not have any fitment issues like trimming the piston skirts in order to clear the crank or the piston not lining up with the cylinder deck.

• 51mm Crankshaft with NTN bearings
• High compression piston with rings, pin, & clips
• Race Head with Large 25/22mm valves and porting for increased performance and big cooling fins.
• High compression piston with rings, pin, & clips
• Lightweight aluminum cylinder with steel sleeve, cast in mounts for skid plates, and large cooling fins.
• High performance race camshaft 
• 26mm MIKUNI Carburetor kit with intake, air filter, and throttle cable. 
• Crankcase and clutch cover gaskets
• Head gasket kit

Exceeds OEM Standard equipment

 Fitment:

• Honda Z50 - 1988-1999
• Honda XR50 - All Years
• Honda CRF50 - All Years

Note:  This kit should be installed by a professional mechanic.