Descrizione O.S.SPEED's off-road racing engine has further evolved. The B2105, which has evolved into the fifth generation of the B21 series, is designed to secure power that gives an advantage in harsh off-road racing scenes, and pursues a driving feel that steadily demonstrates performance in any situation. By re-designing the cylinder liner and crankshaft, we have achieved smooth and linear power delivery. Furthermore, the effect of a lighter outer head successfully improves drivability in any situation. Spec.--------------------------- Displacement： 3.49 cc / 0.213cu.in. Bore: 16.27mm / 0.641 in. Stroke: 16.80mm / 0.661 in. Output :2.68 ps / 2.64 hp / 34,000 r.p.m. practical rpm range: 4,000-42,000 r.p.m. Engine Weight:348g / 12.28 oz. Standard accessories--------------------------- Glow plug T-P3 Reducer φ6Ⅱ、φ6.5Ⅱ Exhaust seal ring Dust cap set 12-30(φ3、φ16、φ18)