O.S. SPEED's off-road racing engine has evolved further, and the fourth generation of the B21 series, the B2104, has been designed to provide the power to take advantage of the toughest off-road racing situations and to deliver steady performance in any situation. It has evolved into an off-road engine that is perfectly synchronized to the movements of your fingertips, from idling to the maximum rpm range. With O.S. SPEED's technical know-how condensed into its entire body, it will once again continue to create a legend in the off-road racing scene.
OS SPEED's off-road racing engine has evolved even further! The 4th generation of the B21 series, the "B2104" is a long-stroke engine that has improved response in the low range, more torque in the middle range as well as consistent idling.
- New piston/liner is a conventional 3-port type enabling more torque over the power range
- The new crankshaft has DLC coating as we always do for OS SPEED engines. The two tungsten counterweights are embedded in the crankshaft contributing consistent idling and quick rpm down according to throttle move
- The thrust plate with surface treatment embedded in the cover plate reduces friction against a connecting rod to extend its life
- The boost port and the exhaust port of the crankcase are redesigned for optimum air flow
- The carburetor is trustable 22E type, which is featured in the OS Engines B2103 Type R
- The cooling head is conventional round-shape type with standard height