This is a Dynamite Mach 2 .21 SG nitro buggy engine, with a combination pull/spin start backplate. Dynamites Mach 2 series engine line ignites the industry with the .21 SG with pull/spin start combo nitro engine. Known for explosive power, reliability and all out performance, Dynamite engines are becoming the engine of choice for many RC sport racers. The 13mm turbo ported crankshaft along with the ABC 6 port piston and sleeve allow this engine to deliver superior horsepower, high torque and extreme efficiency matched only by engines at much higher price points. Engine startup is as easy as utilizing the built in pull start mechanism or by using a spin starter. The Dynamite .21 SG incorporates the technology and design advances developed from the Dynamite Platinum .21 XP in a sport version. Whether you're upgrading your existing nitro vehicle or looking to build a competitive racer, look no further, the Dynamite .21 SG engine has everything you need to be successful in the backyard or at the track. Key Features: 13mm turbo ported crankshaft 2 needle carburetor ABC 6 port piston and sleeve Knife edged connecting rod Pull start/Spin start combo equipped Specifications: Type: 2-stroke Displacement: .21 Bore: 16.27mm Stroke: 16.75mm Engine (Only) Weight: 410g. RPM Range: up to 30,000 HP: 2.3 Front Bearing Size: 7X19X6 Rear Bearing Size: 13X24X6 Cylinder Type: ABC Starting System: Pull start/spin start combination system # of Ports: 6+1 Carb Type: 2 needle slide Crank Type: SG