Eliminate belt slip and improve throttle response with the Naraku CNC Machined Performance Variator Drive Face. Engineered specifically for the 50cc QMB139 (GY6) engine platform, this red anodized aluminum drive face is precision-machined to ensure a perfectly flat contact surface, maximizing belt grip and efficiency throughout the entire RPM range. A direct upgrade over the stock cast face, which develops grooves over time that kill top speed and gear ratio transitions.
Model Compatibility
Fits the 139QMB / QMB139 engine family found in most 50cc 4-stroke Chinese scooters:
- Engine codes: 139QMB | 1P39QMB | 139QMA
- Brands: TaoTao, Wolf, Ice Bear, Bintelli, Kymco, SYM, and other GY6 50cc platforms
Features
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CNC Machined Surface: High-precision finish optimizes the belt's contact patch, reducing friction-based heat and preventing belt slip.
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Red Anodized Finish: Specialized anodizing improves heat dissipation, extending the life of your drive belt and variator rollers.
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26-Spline Center Hub: Manufactured to exact OEM tolerances for a rock-solid crankshaft connection.
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OEM Component Compatible: Works with stock electric start, kick start components, and factory plastic cooling fan.
Specifications
- Material: CNC machined aluminum
- Finish: Red anodized
- Spline Count: 26
- SKU: 137-29 | MPN: NK900.59
Mechanic's Note: The drive face is the outer half of your CVT pulley system. Over time, the stock face develops grooves from the belt that kill top speed — replacing it with this Naraku unit restores original gear ratio transitions. Note: Does NOT include the kick start gear or cooling fan — swap those over from your old unit during installation.
California Prop 65 Warning: www.p65warnings.ca.gov
Model Fitment
GY6 50cc 4-stroke engines: 139QMB, 1P39QMB, 139QMA; TaoTao, Wolf, Ice Bear, Bintelli, Kymco, SYM and other QMB139-platform scooters
