This high quality scooter part is the compression spring for the 50cc 1PE40QMB Minarelli Yamaha Jog Style Scooter Engines from NCY Compression springs will do several things; they supply the pressure to engage the belt, and in addition, they determine the rate at which the CVT transmission changes from low to high gear Description This high quality scooter part is the compression spring for the 50cc 1PE40QMB Minarelli Yamaha Jog Style Scooter Engines from NCY. Compression springs will do several things; they supply the pressure to engage the belt, and in addition, they determine the rate at which the CVT transmission changes from low to high gear. For instance; a 1000 rpm spring will go into a higher gear sooner than a 2000rpm spring. This NCY 1000 rpm compression spring will fit the Yamaha Jog, the Zuma 50cc, and most other Minarelli applications. Let Monster Scooter Parts be your source for NCY scooter parts and accessories. WARNING California Residents : Proposition 65 Warning