GY6 50cc (139QMB) Adjustable Drive Sheave (Premium)

Adjustable Drive Sheave for 50cc CSC Scooters

The Adjustable Drive Sheave is designed for 50cc scooters equipped with the 139QMB engine. This component improves acceleration and increases top speed, making it a valuable addition for riders looking to boost their scooter's performance. It is one of the GY6 50cc scooter parts that can be easily swapped at home, providing noticeable benefits in both speed and torque delivery.

Performance Benefits

This drive sheave features a design with more linear slots, which optimizes the torque transfer from the engine to the wheels. By improving the efficiency of power delivery, it helps increase both acceleration and overall top speed. Riders will appreciate the increased responsiveness during their rides, especially in urban settings.

Installation Details

This component includes the rear pulley, bearings, and nut, making it ready for installation right out of the box. If you're installing it on a CSC go model, be aware that clutch slider pins are required for proper fitment. Ensure that you have the necessary tools and follow standard installation protocols for the best results.

Specifications

• Outer Diameter: 118.7mm
• Inner Diameter: 33.5mm
• Includes: rear pulley, bearings, nut

Fitment

This adjustable drive sheave is compatible with various 50cc and 80cc engines that utilize the 139QMB platform. Below are the specific models it fits:

• CSC Bella Classic 50
• CSC go
• CSC go MAX
• CSC Nitro Sport 50
• CSC Pug 50

It also fits engines with the following codes: 139QMA, 1P39QMB, 1P39QMA-2, YN139QMB, JJ1P39QMB, 139FMA-2, and BD1P39QMB. If your engine has a code that starts with "QM" or "FM", this component is likely suitable for your vehicle.

Not sure it fits? Contact us with your scooter's make, model and year and we'll confirm the fit before you order.

Shop more: GY6 50cc Scooter Parts (139QMB) · GY6 Scooter Parts · Scooter Parts