Dr. Pulley 21x15 Sliding Roller Weights Options:12G Any 139QMB scooter or go-kart

Any 139QMB scooter or go-kart with a carburetor with a 38mm diameter intake

and Black Cat 50

Kit Contents & Specifications

SSP-G Aluminum Drive Face for Honda Elite 50

Zuma 50 FX / Naked (4-Stroke 2012+)

Dr. Pulley 21x15 Sliding Roller Weights Options:12G Any 139QMB scooter or go-kartDr. Pulley 21x15 Sliding Roller Weights for the Vespa GT 200, Vespa GTS 250 and Vespa GTS 300. All weights on sale. Please select weight from drop down menu. Traditionally, gear ratio is changed by the up and down rolling movement of the roller weights in the ramp of the Moveable Drive Pulley (MDF). Now the innovative Dr. Pulley Sliding Roller Weights slide up and down the ramp to change the gear ratio. This unique sliding movement (not rolling)