Honda Grom Stage 3 | DHM Piston, ECU Reflash, and TB Camshaft

DH Motoring

Regular price $275.00

Shipping calculated at checkout.

Customer Reviews

Based on 58 reviews
Grom stage 3 kit

Paired with chimera intake, Vance and Hines hooligan exhaust, 428 sprocket conversion 14/36
Motul Grom Race oil, Sunoco racing fuel 100 octane… Overall bike is bananas you will have no issues Hitting high 80s I’m 6”0 175 and I ride this is NYC Astoria

Travis G

Coupled with the clutch kit from dhm, chimera plate, and some heavier springs. This really woke the bike up. Pulling the front wheel without any clutch and pulling much harder in every gear. So far so good!

Orrin Shattuck
Full. Send. (Stage 3)

I bought this kit and installed it in about 6 hours following the install video. Got it all buttoned up and went for a very painful 20 mile break in cruise, and as soon as 20 miles was up it was game on and I couldn’t be happier. This is not supposed to a superbike, but it feels like it has the heart of one. From the 10k rev limit, to the mild lope the cam has it just sounds mean. And as long as DHM continues to make this kit and sell it at such a good price, I’ll Send it, blow it up, buy another kit, and repeat without feeling the slightest bit bad about it. Thanks DHM!

ray farrell
Honda Grom stage 3 kit

Very easy to install I did the proper 300 miles then I noticed a significant difference very happy with the purchase and installation went like a breeze if you’re looking for a quick and easy upgrade I recommend thanks again night and day difference

Best thing you can do to your Grom hands down

Bought this kit and installed in maybe 3ish hours making sure everything was perfect and with some goofing off included. Need feeler gauges and something to pull the decompression mechanism on the cam (like a small bearing puller)

I have done the airbox mods and have the 85 dollar Amazon exhaust with the baffle removed
I also have a 14tooth front sprocket
I weigh 290 and am 6foot2
This kit still got me to 67mph on flat ground with a full tuck and about 60 sitting upright!!

Am running a little avgas to get the necessary octane number since highest octane I can find in my state is 90, and she rips!!

10/10 would buy again, don't wait it's only 300 bucks

The DH Motoring Stage 3 Package includes the following:

  • DHM ECU Flash
  • DHM High Compression Stock Bore Piston
  • TB Camshaft
  • NGK CR9E Spark plug with spacer

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 ($95 extra), or you can send yours in to be flashed. 

An oil cooler and extra crankcase vents are recommended for this kit. 

We offer the following crankcase vent systems:

AvailMS Crankcase Vent 

MO Power Crankcase Cover