TB 149cc Big Bore Kit, 55mm Forged Piston, & Cam – 2022+ Grom/Monkey12

TBparts 149cc big bore kit for the 2022+ Honda Grom/Monkey 125. This will make your motorcycle a lot more fun to ride by adding some much needed power. With the larger bore, this bolt-on upgrade kit will give you more power and higher compression for a very reasonable price. This kit does not require boring of the case – simply bolt on, tune (Not included) and go!! This is an ideal option if you’re looking to add some power or you just need a new cylinder, piston, and rings to rebuild your engine. Now included with our performance cam for the best value possible!

TBparts performance camshaft for 2022+ Honda Grom, Monkey, CT125, Dax, & Cub. Ideal for use with our bore kit. Designed with more lift to open both valves up more to let more air and fuel in. More air and fuel equals more power! The cam ramp is also more aggressive to open the valves quicker to sneak even more power out! Unleash more power with this modified performance cam grind!

Key features:

High quality, Forged, high compression 55mm piston, with rings, pin, & clips
11.8:1 compression ratio compared to Stock 10:1. Our 11.8:1 piston is pump 91+ octane gas friendly.
Aluminum cylinder with steel sleeve (55mm)
Head gasket kit with exhaust gasket!
Fits all 2022+ Honda Grom/Monkey 125
Largest bore you can go without boring the cases
More power and fun at an affordable price
Clearance to retain factory piston oil squirter
Brand new performance camshaft & cam bearings
Easy bolt-on kit
+4 HP! More gains if you have a performance Exhaust and Intake

There are no installation instructions, but if you can replace your piston, you can install this kit. If you don’t have any experience working on your engine, we highly recommend having a professional technician install this kit or, at a minimum, purchasing the shop manual for your bike. We also have a link on our website in the INFO section under Honda where you can find additional info. The parts are installed in the same manner as the OEM parts.

Notes:

These bore kits are only for the 2022 and newer models (will not work on the 2021 and older models as the engine has been redesigned)
A performance intake and exhaust is recommended if you want to get the most power possible! (Not necessary)
Tuning Required – The ECU will require a flash/tune to prevent a lean condition and possible damage to your engine. CJR Performance (cameronjonesracing.com) provides this service and can also adjust the tune based on your other modifications.
Valve Lash Settings – 0.003″ Intake/Exhaust

This product is legal for closed-course competition use only; for racing vehicles (a competition vehicle not used on public highways). Intended for off-road use or race purposes; may not meet regulations of pollution controlled roads or highways. Not legal for vehicles registered and use in California.

TBparts.com is the only distributor of our products and the parts are shipped directly from the manufacturing facility to us. When a product is purchased from us, it has not gone through several middlemen and thus, the savings goes to the consumer. Additionally, to keep prices down, we use basic packaging and installation instructions are not included. The end result is affordable and high quality performance parts that will add some power and excitement to your bike!