DHM 149cc Big Bore Kit - 2022+ Honda Grom

DHM 149cc Big Bore Kit - 2022+ Honda GromWider skirt bridges for more squirter clearance One additional oil control ring lubrication hole compared to the previous piston Two additional piston skirt lubrication holes compared to the previous piston Compression on pump gas is now 12: 1 to reduce detonation when hot Kit includes: 55mm Forged Piston with ring kit 55mm Sleeved cylinder Base and head gasket set This kit provides a significant horsepower and torque increase across the entire rev

Wider skirt bridges for more squirter clearance
One additional oil control ring lubrication hole compared to the previous piston
Two additional piston skirt lubrication holes compared to the previous piston
Compression on pump gas is now 12:1 to reduce detonation when hot
Kit includes:

• 55mm Forged Piston with ring kit
• 55mm Sleeved cylinder
• Base and head gasket set
  

This kit provides a significant horsepower and torque increase across the entire rev range. Expect gains of 30% in the midrange over a bike with intake, exhaust and cam, and double the horsepower of a stock bike at 8500rpm.

ECU flash or an aRacer MiniX and AF2 combo will be required for proper installation.

ECU Flash located HERE

Required supporting mods other than the ECU tuning:

• Camshaft: DHM S1 Camshaft or DHM S1R Camshaft
• Crankcase Vent: MO Power Vented Cam Cover
• Oil Cooler: Kitaco x DHM Oil Cooler Kit
  
• Injector: PCX150 Injector
• Spark plug: NGK CR9E

Two base gaskets included. Use both the OEM Honda base gasket and the grey paper gasket for pump fuel setups, use only the OEM Honda base gasket for race fuel.
Oil coolers are required. Keep an eye on oil temps.
An NGK CR9E spark plug must be used
Ring gaps must be set during install, please see the setup sheet for further info.
91 octane is the bare minimum, and 93 is preferred.