Over the last few years we have seen a huge increase in youth riding, and our managing editor, Mark Tilley, is right in the middle of it all with not just one but two boys. Austin and Jacob are both riding and racing, so Mark is neck-deep in small-displacement two-strokes. Jacob Tilley is 11 and rides the 65cc class at local MX and off-road events, so we took a GasGas MC65 test bike and built him a race machine.

2021 is the first year that GasGas has produced a 65cc machine under its new ownership. It’s no surprise that it resembles its 65cc brothers from KTM and Husqvarna; as a matter of fact, they are more alike than they are different. That’s a good thing, because these machines have a great reputation for reliability, and the number of aftermarket products available is mind-blowing. We decided to play it safe with this build and not go overboard.

Jacob Tilley twisting the throttle on his GasGas project.


The first thing you have to keep in mind when building a bike for the younger generation is to be honest with yourself about the ability of the rider and build accordingly. Engine-wise, we worked with Jamie Ellis and his crew at Twisted Development. These guys can produce major horsepower, and do so for many of the top amateur and professional riders today.

With our build, it was all about good, reliable power, because Jacob is racing a variety of events and riding this bike for practice as well. A new top end was installed, and then the calculations on proper squish (mini two-stroke dads know all about this) commenced with what combination of base gaskets to use. The only other major internal modification done was the installation of a complete Rekluse clutch that can be used in an automatic application or full manual, just like stock, and comes with a hard-anodized clutch cover and slave cylinder.

With some help from key industry leading companies this Gas Gas MC65 build turned out awesome.


We installed a Pro Circuit exhaust system featuring a platinum pipe and R304 factory sound shorty silencer. The OEM exhaust manifold was replaced with a billet-aluminum model produced by Twisted Development that’s designed to retain the bottom-end grunt that the stock pipe produces without taking away the top-end power the aftermarket pipe manufacturers are going for. Twisted Development would also run the bike on the dyno and re-jet the carburetor before they gave it back to us.    

Just like bigger bikes, mini bikes hammer chassis parts, and it’s something that a lot of people will often overlook until it’s too late. The aftermarket world has responded to this need by making OEM replacement and performance parts available.

Tilley was all smiles with the finished product.


We didn’t go overboard, suspension-wise, we just made sure all the wear parts were replaced. It’s sometimes hard to get feedback from smaller riders when it comes to suspension, so we decided not to tackle that on this build. The OEM wheels were upgraded with units from Kite that feature billet-aluminum hubs anodized red with stainless steel spokes and black Excel Takasago rims.

Ryan and the crew at Throttle Syndicate gave our MC65 a clean look with Fasthouse graphics and a complete set of Acerbis plastics.


The Kite complete wheelset is basically a scaled-down version of what is available for larger machines and can handle tons of abuse.


ProX brake rotors and sprockets replace the well-worn stock items. The OEM chain sliders are some of the best on the market, but even with that said, the TM Designworks units are highly recommended upgrades and can be customized with a variety of colors available.

One item that commonly gets overlooked on smaller machines is handguards. We aren’t sure exactly why, but we made sure that didn’t happen here with a combination of Cycra folding MX mounts and P3 Carbon shields that added some bling factory as well.

Nihilo Concepts, Pro X and TM Designworks were all key parts of our drivetrain upgrade.


Giving your mini ripper power or handling that they aren’t ready for can actually hurt their riding experience. With this build, we wanted to give test rider Jacob Tilley the right tools that can help progress his riding gradually rather than make the bike difficult for him to ride. Jamie and the crew at Twisted Development dialed the new top-end, Pro Circuit exhaust and their CNC-machined billet-aluminum exhaust manifold fit perfectly together. Overall power was increased across the powerband, with the biggest gains felt in the midrange and on the top end.

Internally engine modifications were limited, but trust us, Jamie and the crew at Twisted Development made sure it made plenty of power.


The Rekluse clutch started out as a fully automatic version but during testing has been slowly transitioned into a full manual mode. This design feature is great, especially for kids just learning the concept of a clutch and is definitely something that we recommend highly.

If you have a rider new to the concept of a clutch, the full Rekluse setup can be a huge help with this transition.
The Specbolt Nickle Wurks dress up kit makes a huge difference in appearances


We are very impressed with companies like Pro Circuit, Nihilo Concepts, Kite, ProX, ODI, TM Designworks, and the rest of the aftermarket companies for making parts for the next generation of racers. For more projects like this one, head over to Dirt Bike’s website ( and check out our “Two-Stroke Tuesday” feature.

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