Trail Bikes 108cc Stroker Crank Kit 3, Conversion 12 volt - Z50 (88-99),  XR50 / CRF50 XR70 / CRF70 / CT70

Honda TB Parts 108cc Stroker Kit 3 - Complete Conversion from Stock

Fits:
Honda Z50 (12 Volt)
Honda XR50, CRF50, XR70, CRF70

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).

Includes:

     - 51mm Crankshaft with NTN bearings. Crank, 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.
     - High compression piston with rings, pin, & clips
     - Race Head, Larger valves (now 25/22mm) and better flow for increased performance. Also has bigger cooling fins.
      Includes all necessary parts and comes assembled!
     - Lightweight aluminum cylinder with steel sleeve, cast in mounts for skid plates, and larger cooling fins.
     - High performance race camshaft
     - Genuine Mikuni VM26mm Performance Carb (includes Intake)
     - Jet kit with 3 different sizes (Stock size is a #195 - Extra jets sizes of 155, 165 & 175)
     - Throttle Cable
     - NEW Dual Layered Foam Air Filter
     - Crankcase and clutch cover gaskets
     - Head gasket kit

You should also consider the following parts:

     - High volume oil pump (see Part# TBW0226)
     - Oil Cooler (see Part# TBW0982)
     - CR8HSA spark plug (not required, but recommended)
     - Manual Clutch Kit (see Part# TBW0953 )

Above recommended parts should be accessible at the bottom of this page...

Additionally, we DO NOT recommend the use of an inner rotor kit with this clutch (on a 108cc or larger engine) as it can lead to premature clutch failure due to extra fatigue placed on the clutch housing.

However, we offer an upgrade which allows use of inner rotor kits and larger displacement engines - Please see the Billet Housing upgrade we have available for more details. Part# TBW0429


This kit requires the engine to be disassembled. We highly recommend a professional technician install this kit.
Keep in mind, Fast50s offers mechanical services for a very reasonable rate!

If you plan on doing it yourself, you will need to have at a minimum a Clymer or Honda shop manual.
Instructions do not come with the kits but the installation of the crankshaft is similar like installing a stock Honda crankshaft.
Remember when installing: Only torque on the clutch nut with the proper tool! No "backwoods" hammer and screw driver! Ha!