DHM High Compression Stock Bore Piston (Gen 2) for 2014-2020 Honda Grom and 2019-2021 Honda Monkey

DH Motoring Stock Bore Racing Piston (Gen 2)The DHM Race-spec stock bore piston has produced more HP than any other stock bore kit and is the highest compression stock bore piston on the market. It has a high compression dome that is made exclusively for us and isn't available anywhere else. It's gone through extensive testing on the racetrack and has proven to provide the most power possible from the stock bore.  ~13.2:1 compression 52.4mm stock bore piston Larger ring and skirt oiling holes than other pistons on the market Larger oil spring to increase oil volume between the oiling rings Oil ports under the pin holes to keep the wrist pin lubricated 360 Degree skirt design to increase overall strength Racing piston ring kit with pins and circlips Valve reliefs that clear valves up to 27.5/23.5 cylinder head valves Includes a new base gasket and head gasket Requires NGK CR9E (6263) spark plug  Requires at least 91 octane fuel Over the past 6 years we've raced with and tested over a