Polini performance CVT torque spring for the Yamaha Zuma 50 and Minarelli-based 50cc scooters. Runs 15% stiffer than stock, applying constant lateral pressure against the rear pulley sheaves to keep the drive belt loaded within the optimal powerband. Eliminates mid-range transmission lag, sharpens throttle response, and improves back-shift response on deceleration. Made in Italy.
Off-road use only. Not intended for use on public roads or land.
Tuning note: A stiffer torque spring alters CVT balance. If the transmission stays in a low ratio too long or over-revs, increase roller weight slightly to counterbalance the new spring rate.
Installation tip: The rear clutch pulley is under heavy internal tension. Always use a dedicated clutch compressor tool when loosening the retaining nut.
Features
- 15% stiffer than stock — raises shift RPM to bypass factory flat spots
- High-tensile silicon-steel alloy — resists spring sag and thermal fatigue
- Improves back-shift response on deceleration
- Made in Italy by Polini
Specifications
| Spring Rate |
+15% over OEM stock |
| Material |
High-tensile silicon-steel alloy |
| Color |
Blue |
| MPN |
243.093 |
| Brand |
Polini |
| Origin |
Made in Italy |
Model Fitment
| Brand |
Models |
| Yamaha |
Zuma 50 2T, Zuma 50F / 50FX / C3 / Vino 4T, Jog 50 / Jog RR |
| Genuine Scooter Co. |
Buddy 50, RoughHouse 50, Rattler 50 |
| Aprilia |
Scarabeo 50 2T, SR 50 (Minarelli) |
| Adly / Keeway / Eton |
Beamer, Matrix, F-Act, Hurricane, Viper 50 |
California Prop 65 Warning: www.p65warnings.ca.gov