Replacement forged piston set. Fits all 100\" and 107\" 4\" bore Super Sidewinder engines. Will also fit the special (out of production) 100\" Evo type retro-fit engine for Shovel chassis, which is equipped with small diameter flywheels. Incl. pistons, wrist pins, wristpin clips and piston rings. Note: In any and all applications the technician must be able to judge components for their suitability in combination with the other engine components, prior to installation. It is of importance that a knowledgeable mechanic will install & make adjustments as required. The rider must follow standard break-in and riding procedures for overhauled engines.