Prima 16x13mm CVT Roller Weights | 139QMB Ruckus Buddy 50

Selecting optimal roller weights for your personal preference will deliver the most cost-effective performance upgrade you can make to a CVT scooter. The Prima 16x13mm Roller Weight Set (6 per pack) is precision-manufactured to exact tolerances for smooth, consistent shifting and long-term durability in high-heat CVT environments. Whether you want snappier off-the-line pull or a higher top-end cruise, swapping rollers gets you there without touching the carb or exhaust.

CVT Tuning Guide

Choosing the right weight depends on your riding goals and body weight:

• Lighter Weights (3g–5g): Quicker acceleration, better hill climbing, ideal for heavier riders. May slightly reduce top-end speed.
• Mid-Range Weights (6g–8g): Balanced daily commuting — closest to stock feel for most 50cc scooters.
• Heavier Weights (9g–11g): Higher top-end speed on flat roads, best for lighter riders. Acceleration will be more gradual.

Technical Specifications

• Diameter: 16mm
• Width: 13mm
• Quantity: 6 weights per pack
• Compatibility: Standard variators requiring 16x13mm rollers

Compatibility

Direct replacement for 49cc–80cc 4-stroke (139QMB / GY6 50) engines and premium 50cc models from Genuine, Honda, and Yamaha.

Genuine Scooter Co. (2-Stroke):

• Buddy 50 / International: Stock 7.5g–8.5g
• RoughHouse 50 / Sport / Titanium: Stock 7.5g–8.5g
• Rattler 50: Stock 11.5g
• Black Cat 50: Stock 7.5g–8.5g

Honda & Yamaha (4-Stroke):

• Honda Ruckus (NPS50): All years
• Honda Metropolitan (CHF50): 2002–2012
• Yamaha C3 (XF50): 2007–2011
• Yamaha Vino 50: 4-stroke models
• Yamaha Zuma 50F / 50FX: 4-stroke models (2012+)

Chinese & Taiwanese 50cc (GY6 50 / 139QMB):

• Chicago Scooter Co. Go. 50, Go. Max 50
• Wolf Brand Scooters: RX-50, Islander, Lucky, Blaze, MOTO
• TaoTao / Tao Motors: ATM50-A1, Pony, VIP, Thunder
• Lance / SYM: Cali Classic 50, PCH 50, Cabo 50
• Kymco: Agility 50, Super 8 50 (4-stroke)
• Bintelli / Ice Bear: Breeze, Havoc, Maddog 50, PMZ50

Engine Code Compatibility

Don’t see your model? If your engine tag contains any of the following codes, these 16x13mm weights are compatible:

California Prop 65 Warning: www.p65warnings.ca.gov

• Precision-manufactured to exact tolerances
• 6 weights per pack
• Available in 3g–11g for full CVT tuning range
• Fits standard 16x13mm variators
• High-heat CVT environment durability

Diameter: 16mm | Width: 13mm | Quantity: 6 per pack | Weight options: 3g, 3.5g, 4g, 4.5g, 5g, 5.5g, 6g, 6.5g, 7g, 7.5g, 8g, 9g, 10g, 11g | Fits: 16x13mm variators

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