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DHM 186 ALL INCLUSIVE BIG BORE KIT

$645.00
Camshaft
Would you like a preflashed ECU?
Would you like a TB clutch kit?

 

We are proud to introduce the first "all inclusive" big bore package for the Honda Grom!

The DHM 186 kit includes everything you need to convert your Honda Grom in to a big bore machine. You no longer have to piece parts together with expensive components to get more power out of your bike. Our kit utilizes hardware from TBParts along with an OEM Honda injector and our software tuning to create a reliable and powerful kit that makes the Grom easier and more fun to ride. 

Included:

  • 186cc Cylinder and Piston
  • Complete Oil Cooler Kit
  • OEM Honda PCX150 Fuel Injector
  • DHM Reflash
  • TB Camshaft or Decha HR Camshaft (you can select an option to reduce the price if you already own one)


Performance Data:

  • 16.5 HP and 14.5 Ft/lbs of torque! A gain of 74% in HP and 67% in torque over a stock bike. (Dyno chart available in photos above)
  • 20-50mph in 5 seconds compared to a stock bike at 9 seconds



Options: 

TB or Decha HR Camshaft. This kit is designed to be run with the TB or Decha HR camshaft. If you already have one, you do not need to select it. If you do not already own one, please add it by using the drop down menu when ordering.

TB Clutch Kit. If your stock clutch is worn, or you'd just like a harder bite, we offer the TB clutch kit as a $40 upgrade.

How the Reflash works: 

You will need to send us your ECU to be reflashed for proper fueling to run with the kit. If you do not wish to send us your ECU, we can provide a core ECU for an additional fee. Please select your ECU option from the drop down menu when ordering. You can receive a refund of $50 when returning your ecu if you order a core when checking out.

Since our primary business is building race engines, we take a lot of pride and care in our engine assembly. Before shipping, we will check all ring gaps, and we will also align the rings in the piston and install the piston in to the cylinder for you with the alignment we recommend! 


**An upgraded intake and exhaust are not required but are highly recommended!


Completely upgradeable:

Since we are flashing the OEM ecu, you can still use piggybacks on top of this kit should you decide to make any changes. If you would like to add a big valve head or change the cam, etc., you can do so and use your piggyback fuel controller (pcv, etc) to tune it as you normally would. The fact that we've reflashed the stock ecu for fuel and timing will actually provide a better base than the stock, unmodified ecu! 

***Requirements and General Information:

The ECU reflash requires your stock narrowband O2 sensor to be installed and plugged in. If you have removed this to use another fuel controller, you will need to reinstall it. The ecu will learn and adapt over the first 15-20 miles, so acceleration and overall ride ability will increase up to that point. 

Installation instructions are not included. If you are not capable of working on these engines, having a shop perform the install is recommended.

This kit is designed to be bolt-on, reliable power. However, at the end of the day the Grom engine is a very simple air-cooled engine, and heat is the enemy. If you plan on taking regular highway trips, an oil temperature gauge is highly recommended to make sure the engine does not overheat. OPMID and Koso both offer great options.

Customer Reviews

Based on 74 reviews
88%
(65)
5%
(4)
4%
(3)
1%
(1)
1%
(1)
D
Drew Spence
186 Big Bore Kit

Hard to give a review after only 21 days, will have to see what reliability is like after 21k. The install went well and was simple enough if you can wrench. Everything was included and everything fit nicely. Should maybe come with a colder spark plug and the tune they sent me does not run the bike well until it is completely warmed up. It will stall every single time you let off throttle, which can actually be super dangerous in some situations. Will probably have to buy an ARacer to run it properly and spend another $450. Also the way the oil cooler is installed inside a cage without any rubber isolators makes the oil cooler rattle the entire drive and is very annoying. The power and sound it gives are absolutely amazing, I can't complain there. Pretty good kit. Prettyy prettyyy good.

D
Dan t
Honda grom bbk 186 kit

Besides the oil cooler came damaged also would be better if it came with longer oil cooler cables so you can run it on the other cover not so low to the ground would be ideal
I can’t fault it just not 5 stars with damaged goods
Runs good until my clutch started slipping even with the heavy duty clutch upgrade clutch cable is to small with the pro taper bars so just ordered a longer cable so hopefully that clutch last longer then one ride
Got rid of the ticking so that’s a bonus was 1 tooth off tdc

J
John P.
Honda Grom as it should be

I was looking to upgrade the motor so I could get up to speed faster this Kit did that and more! Straight forward install. The team was great with communication.

W
Wesley Chandler
186 bbk kit

Absolutely awesome people at dhm very helpful and very strait forward and easy kit!! My only regret was not doing it sooner! Also get the upgraded spring and lifter plate for ur clutches. U will most def need them

M
MICHAEL HARTLEY

DHM 186 ALL INCLUSIVE BIG BORE KIT