TBParts - Vintage Honda 108cc Stroker big bore & Nibbi 24mm Carb kit
69-79 CT70 3 speed

108cc Stroker Crank with Race Head Kit w/ Nibbi 24mm carb kit

This kit is the complete kit to convert your stock motor into a powerful open class 108cc engine. 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.

Race Head has been updated for even more performance! It now has 25/22mm valves with better porting/flow. We also kept the combustion chamber the same size and changed the angle of the valves slightly.

Please see the Billet Housing upgrade available in this section for more details. Also, do not tighten the clutch nut with a hammer and screw driver - it must be torqued on!

This kit requires engine disassembly and therefore, we highly recommend a professional technician install this kit. If you plan on doing it yourself, you will need to have a Clymer or Honda shop manual. Instructions do not come with the kits but the installation of the crankshaft is just like installing a stock Honda crankshaft.

We recommend purchasing the Upgrade Disk Kit for your TB manual clutch. 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

Key features:

• 51mm Crankshaft with NTN bearings. Crankshaft measures 57mm from gear to end.
• 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
• Nibbi 24mm Carburetor kit with intake, air filter, and throttle cable.
• Crankcase and clutch cover gaskets
• Head gasket kit

• High volume oil pump - TBW0225-6V
• High speed 2mm drill bit - TRC-5526
• 2 Size clutch tool - WHS-2274
• TB oil cooler kit w/ intake mount - TBW1370
• Sta-bil fuel stabilizer - W-57-1129
• 12 Way rotating spacer - TBW0900

• CT70 3 speed - 69-79

• TBW0622 - Crank
• TBW0365 - Piston
• TBW0225 - Oil Pump
• TBW0287 - Gasket
• TBW0334 - Gasket
• TBW0206 - Gasket
• TBW0273 - Intake
• TBW0301 - Throttle
• NB-PE24YJ - Carb
• W-78-9455 - Air Filter
• TBW0327 - Jet Kit
• TBW0385 - Race Head and Valves Assembly
• TBW0251 - Right Side Cover
• TBW0189 - Cam
• TBW0156 - Cylinder
• TBW0861 - Cam Sprocket