Most Grom owners would be satisfied with their machine’s 125cc powerplant. Others, however, are more adventurous. Vasily Builds initially put a 200cc motor in his Grom, but after one long stint going flat out at 90 miles per hour, the engine he initially put in went kaput.
The suspected failure point was with the piston of the 200cc motor. The engine lost compression which was a terrible and horrible sign for its future and later in the video, we see Vasily opening it up and revealing a big gaping hole punched into the piston.
So instead of putting in another 200cc motor to replace the one that was dusted, Vasily Builds decided to go for a 500cc two-stroke Banshee engine.
Yeah, that’s right, he went for more than double the displacement. The 200cc motor was already a two-stroke, which meant that the Grom’s first engine swap was already a fast one, but for the second time around, it was time to go faster.
While waiting for the engine to be sent over, a new set of bearings were installed into the repainted wheels along with a new set of tires. Following that, a new subframe was fabricated for the little Honda, as the engine that was to be fitted wasn’t meant to fit the Grom’s chassis.
A few choice parts were picked out for the build in order to bring it closer to his goal of making it look like a mini MotoGP bike.
Following that, the second video opens up with the installation of the new motor, and it concludes with a first ride.
The next video opens up with an issue but with a few more mods. Unfortunately, a few gears in the transmission got chewed up so parts were ordered the last time the bike was ridden and then it was off to the next video.
So the next video starts with addressing the transmission issue, then it continues on with a test ride which included acceleration tests and a top-speed run. The bike almost hit a hundred miles per hour on the GPS speedometer.
The final video’s all about the other final touches, refining the ride, and more flybys. By the end of it, the Grom was literally flying and screaming all the way to the extro.
Sources: YouTube - Vasily Builds Part 1 , YouTube - Vasily Builds Part 2, YouTube - Vasily Builds Part 3, YouTube - Vasily Builds Part 4, YouTube - Vasily Builds Part 5