GASGAS 500 2-STROKE: PROJECT BIKE SPOTLIGHT

Open-class two-strokes are all but extinct. The Japanese manufacturers stopped making them in the early 2000s, and now the parts for those iconic machines are no longer available. However, the aftermarket community is refusing to let the 500cc sector die out completely. As a matter of fact, companies like BRC Racing and mXrevival are giving it a huge shot of adrenaline. This GasGas MC500 is a testament to just that.

This build started with the purchase of a slightly used 2023 GasGas MC250 from Carl’s Cycle Sales in Idaho. Overall, the machine was in great shape, but Charles at mXrevival had some huge plans for it from the start—double the displacement, give it an all-new look and make it handle like nothing else on the planet. Pretty standard goals, right?

Doubling the displacement might sound completely crazy, but that might have been the easiest thing to accomplish on this project with the help of Riley and the crew at BRC Racing in Canada. The BRC’s 500cc engine conversion is designed to bolt right into the last-generation KTM, Husqvarna and GasGas steel frame without major modifications. Select “donor” internal (complete transmission with clutch) and electrical parts were needed from the MC250 engine. We did have to source out all the electric starter parts from KTM, because our donor engine was a kickstart-only model. Tony Jeske from Elite Moto Factory handled all the assembly of the BRC engine kit and the switching over of parts from the MC250 engine that was needed.

With the addition of big power, it’s never a bad idea to upgrade the suspension, brakes and drive, too. Brandon at AHM Factory Services handled all the suspension needs for the Helfyre project. AHM custom anodized the stock fork tubes and shock body gold, and they also DLC-coated all of our lower shafts. Perhaps the most substantial modification AHM performed was they fully converted the guts of the AER air fork with the complete Yamaha KYB/SSS spring components.

Just when we think we have seen it all, something comes along that surprises us and makes us just stand back and enjoy the finished product. What’s really great about this BRC Racing engine conversion is that we were able to not only double the engine displacement, but the BRC kit also allows us to keep a counterbalanced, exhaust-valve-equipped engine and add electric start to this once “kick-only” GasGas model.

Overall performance of the BRC engine is very impressive and has good tractable power. Just like most big-bore configurations, short-shifting using the midrange meat of the powerband produces the most smiles. The Lectron metering rod-style carburetor does take some time to dial in, and admittedly we never got it perfect all around. Brandon and his crew at AHM Factory Service absolutely nailed the suspension setup! Not only does it have that trick factory look that is provided with all the different specialty coatings, but it performs as good as it looks. We enjoy working with Charles and all the companies he incorporates into the builds he does, and we have a lot more projects planned with him in the future, you are definitely going to want to stay tuned for what is next.