This kit makes the grom what it should have been from Honda. It doesn’t make the grom something it isn’t but it makes it fast for a Grom. The full RPM range is usable now and the upper RPM range is the most fun- like any sport bike. It really wakes up over 7,000 RPM which is awesome because stock the Grom falls on its face over 7,000 RPM. Only time will tell how reliable it is in the long run but I’m happy.
I'm not the most technically minded person, but with some youtube videos and a friend, I got it all together (remember to file down the correct size gaps for the piston rings).
The bike now happily does 70 mph, and I'm yet to change the sprocket. Heat is staying down. So far I'm very happy - five stars.
Honda Grom Stage 3 | DHM Piston, ECU Reflash, and TB Camshaft
Excellent products, world class service, and faster than expected turn around time
I'm able to get up to 70 on flats, now, as opposed to only downhill, but getting up to highway speeds is much quicker! The PCX150 injector does not work with this kit, though. Found that out the hard way.
The DH Motoring Stage 3 Package includes the following:
DHM ECU Flash
DHM High Compression Stock Bore Piston
TB Parts Camshaft
NGK CR9E Spark plug with spacer
Honda Monkey Stage 3 kit is available HERE
Combined with your aftermarket intake and exhaust, this is the most you can get out of your Grom without doing any head work. After dyno testing we were repeatedly seeing 13.5hp at the wheels (SAE) run after run! The Stage 3 package makes more power than a stock Grom at every RPM and double the horsepower at 9000+ rpm! 91 octane fuel is absolutely required. Any fuel with a lower octane rating may result in engine damage!
You can choose to receive a preflashed ECU instead of sending yours in. You can also choose to receive a new cylinder matched to the piston if yours is worn.
This product page is for customers that do not currently have a DHM flash or cam package. If you already own our reflash or cam package, you can purchase the Stage 3 Upgrade HERE.