O.S.SPEED B2105 Off-Road Racing Engine (OSMG2160)

The O.S.SPEED B2105 Off-Road Racing Engine is the fifth generation in the B21 line, designed to deliver strong, reliable power for demanding off-road RC racing and to maintain stable handling across tough courses.

It features a redesigned cylinder liner and crankshaft for smooth, linear power delivery, plus a lighter outer head to sharpen drivability. The 3-port cylinder with revised port shapes boosts mid- to high-end torque, while the crankshaft carries a DLC coating to enhance durability and performance. Reduced outer-head weight improves throttle response, and a proven ceramic bearing sits inside the case. A specially treated thrust plate reduces wear between the rotating connecting rod and the cover plate, helping extend engine life, with internal geometry refined for stronger power characteristics compared with the previous generation.