Polini Primary Up-Gear Kit for Yamaha Zuma 4T 50cc

Polini Primary Gear Set for Yamaha Zuma 4T 50cc

This Polini primary gear set is made to match the Yamaha Zuma 4T 50cc. It uses a 16-tooth helical drive shaft paired with a 51-tooth spur-cut crown wheel. With this set, the gearing is raised, which can help top speed when the engine has enough power to use it. It is one of the Yamaha Zuma scooter parts you can fit to change how your scooter rides.

Construction Details

The primary drive shaft is polished and built from high-strength steel alloy. It has a long splined shaft with stepped journal sections so it seats securely. The crown wheel is spur-cut, has a splined bore, and carries a phosphate finish for lasting wear and quiet, even running.

Performance Improvements

This set takes the place of the stock primary gears and provides a Z=16/51 ratio, allowing the engine to work with higher gearing. Machining is precise, giving tighter tolerances than standard OEM parts, which contributes to durability and smoother engagement.

Specifications

• Polini Part Number: 202.1406
• Gear Type: Primary transmission set
• Ratio: Z=16/51 (16T drive shaft / 51T crown wheel)
• Drive Shaft: Helical-cut, polished steel
• Crown Wheel: Spur-cut, phosphate finish
• Material: High-strength steel alloy
• Fits: Yamaha Zuma 4T 50cc (Minarelli-Yamaha 4-stroke liquid-cooled engine)

Fitment

Fits:

• Yamaha Zuma 4T 50cc (Minarelli-Yamaha 4-stroke liquid-cooled engine)

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