Universal Parts CVT Torque Spring | 139QMB 50cc venture rack 15x10" aluminum wheel in a

15x10" aluminum wheel in a clean satin black finish

Compatibility: Models below and bikes with 2T horizontal Minarelli engines

and dirt bikes equipped with 47cc or 49cc 2-stroke engines using an angled elbow throttle cable

Universal Parts Rocker Arms for use on heads with 69mm Valves found on 50cc 4-stroke QMB139 engines

Has 4 prongs

Universal Parts CVT Torque Spring | 139QMB 50cc venture rack 15x10" aluminum wheel in aRestore proper CVT engagement and shift behavior on your 50cc scooter with this Universal Parts replacement torque spring for 139QMB 4 stroke engines. The torque spring sits inside the rear driven pulley (clutch side) of the CVT and controls the rate at which the belt rides up the pulley faces as engine load increases. A worn or fatigued spring causes sluggish acceleration, belt slip, and poor top speed engagement replacing it restores factory CVT