O.S. SPEED .21 XZB

Speed-tuned for championship-caliber performance! Countless champions, including Mark Pavidis and Atsushi Hara, have trusted O.S. Speed engines to give them a competitive edge. Now, O.S. is proud to continue that winning tradition with the 21XZ-B Speed! A specially designed black-anodized cylinder head improves cooling and reduces weight, while an upgraded, DLC-coated crankshaft improves fuel flow. It all adds up to yet another exceptional, Speed tuned engine from O.S. Unparalleled, speed-tuned power characteristics. Lower fuel consumption – offering 8% longer run times than the standard 21XZ-B. Race-proven 3-port sleeve with special Speed version inner head and porting for smoother acceleration. Tough, DLC-coated crankshaft features a silicone-filled intake passage for improved fuel flow. New 21J2(B) three-needle carburetor includes 6 mm, 6.5 mm and 7 mm restrictors for fine-tuned control. A lowered center of gravity provides steadier vehicle handling. Long stroke allows for superior torque. A black anodized crankcase with ceramic ball bearings helps reduce resistance and increase performance.