The O.S.SPEED B2104 is a long-stroke engine, bore x stroke is 16.27 x 16.80mm. It has quicker response in low range and more torque in middle range with consistent idling. A combo set is equipped with TB03 (T-2100, EFRA 2155) silencer with 80mm manifold (MB-01-80)Piston/Liner:The piston/liner is con..