O.S. Speed 21XZ-B Spec II

O.S. Speed 21XZ-B Spec IIThe O.S.SPEED 21XZ-B is used by many of the worlds top drivers due to its high performance level and has achieved excellent results at many major races including podium positions at the last two World Championships.

Succeeding the popular race proven O.S.SPEED 21XZ-B performance has been increased to meet the ever improving demands of top level racing.

A new drop-in type outer head with special laser marking contributes to lower CG and increased cooling efficiency. Each inner part has been modified to aid in smoother acceleration all through the rev rang up to top speed. A new lighter piston and connecting rod contribute to give a better throttle response. A new lighter DLC coated, tungsten weight pressed-in and silicone potted crankshaft reduces friction loss further for maximum efficiency. Thanks to all of this the O.S.SPEED 21XZ-B Spec.II is born to win races.

• New lighter piston and connecting rod
• New crankshaft features lighter weight, DLC coating, tungsten weight and silicone potting for optimum rotating mass
• New outer head features low CG and better cooling efficiency.
• Well-established 21J double-adjust carburettor is employed. 6mm, 6.5mm and 7mm restrictors are supplied as standard.

Includes:
• P3 Glow Plug
• Carburetor Reducers (6.5mm installed, 6mm and 7mm supplied)
• Exhaust Seal Ring
• Dust Cap Set (3mm/16mm/18mm)