Naraku Performance Variator Drive Face: 139QMB / GY6 50
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Precision Grip: Naraku Machined Performance Drive Face
Eliminate belt slip and improve throttle response with the Naraku Machined Variator Drive Face. Engineered specifically for the 50cc QMB139 (GY6) engine platform, this high-performance component is the definitive upgrade for riders seeking smoother power delivery and increased drivetrain reliability. Unlike standard cast faces, this Naraku unit is precision-machined to ensure a perfectly flat contact surface, maximizing belt grip and efficiency throughout the entire RPM range.
Technical Performance Features
- CNC Machined Surface: Features a high-precision finish that optimizes the belt's contact patch, reducing friction-based heat and preventing power-robbing belt slip.
- Enhanced Heat Dissipation: The specialized anodized finish and optimized geometry help pull heat away from the CVT system, extending the life of your drive belt and variator rollers.
- 26-Spline Fitment: Manufactured to exact OEM tolerances with a reinforced 26-spline center, ensuring a rock-solid connection to the crankshaft.
- OEM Component Compatible: Designed to work seamlessly with your stock electric start, kick start components, and factory plastic cooling fan.
Comprehensive Fitment Guide
This drive face is a performance upgrade for the 139QMB / QMB139 engine family found in:
| Engine Type | Common Brands |
|---|---|
| 50cc / 49cc 4-Stroke (GY6) | TaoTao, Wolf, Ice Bear, Bintelli, Kymco, SYM |
| Engine Codes | 139QMB, 1P39QMB, 139QMA |
Technical Specifications
- Material: CNC Machined Aluminum
- Finish: Performance Anodized (Red)
- Spline Count: 26
- Vendor: Naraku
Mechanic's Note: The drive face is the outer half of your transmission's "pulley" system.
Pro Tip: Over time, the stock face develops "grooves" from the belt that kill your top speed. Replacing it with this Naraku unit restores your original gear ratio transitions.
nstallation Hack: This face does NOT include the kick start gear or fan—make sure to swap those over from your old unit or grab a fresh Kick Start Claw if yours is worn!
SKU: 137-29
MPN: NK900.59
Vendor: Naraku
Shipping information
Orders are prepared as quickly as possible. Delivery times and shipping costs are calculated at checkout based on the destination and items ordered.
Returns & warranty
Please verify fitment and part number before ordering. Contact Thrifty Scooters promptly if an item arrives damaged or incorrect.