Prima 15x12mm Roller Weight Tuning Kit 2g-13g | 36-Piece

The Prima 15x12mm roller weight tuning kit gives you 36 color-coded rollers — 3 of each weight from 2g to 13g — to dial in your CVT transmission for your riding style, engine build, and rider weight. Designed for Yamaha Jog/Zuma/Vino/C3 50cc 2-stroke engines and Minarelli clone motors (QMB139 horizontal). Made in Taiwan. SKU: 1400-1083.

• 36 rollers total — 3 of each weight from 2g to 13g in 1g increments
• Color-coded by weight for easy identification
• Mix and alternate weights to achieve half-gram increments (e.g., alternating 10g and 11g = effective 10.5g)
• Lighter weights: higher RPM for a given speed — better acceleration
• Heavier weights: lower RPM for a given speed — higher top speed
• Fits 15x12mm variator roller pockets
• Made in Taiwan by Prima | SKU: 1400-1083

Tuning Guide

• Lighter (2g–6g): higher RPM, stronger acceleration — best for heavier riders, stock motors, or hill climbing
• Heavier (7g–13g): lower RPM, higher top speed — best for lighter riders or big-bore builds
• Mixing weights: alternate two adjacent weights in the variator to achieve half-gram increments
• Always install rollers in a 120-degree pattern (every other pocket) — uneven installation will cause vibration and variator damage

Specifications

• Roller Dimensions: 15mm diameter x 12mm width
• Weights Included: 2g, 3g, 4g, 5g, 6g, 7g, 8g, 9g, 10g, 11g, 12g, 13g (3 of each)
• Total Quantity: 36 rollers
• SKU: 1400-1083
• Origin: Taiwan

Compatibility

For stock roller weight reference, see our roller weight chart. Additional tuning tips on the Scooterworks blog.

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

• 36 rollers total — 3 of each weight from 2g to 13g in 1g increments
• Color-coded by weight for easy identification
• Mix and alternate weights to achieve half-gram increments
• Lighter weights: higher RPM and acceleration | Heavier weights: higher top speed
• Fits 15x12mm variator roller pockets
• Made in Taiwan by Prima | SKU: 1400-1083

Dimensions: 15mm x 12mm | Weights: 2g–13g (3 of each, 36 total) | SKU: 1400-1083 | Origin: Taiwan

Yamaha Jog 50 2T, Yamaha Zuma 50 2T, Yamaha Vino 50 2T, Yamaha C3 50, Minarelli clone engines (horizontal) — engine codes: 1E40EQMB, 1E41QMB, 1PE40QMB