GY6 Engine Gear Sets

Performance Gear Sets for GY6 125cc and 150cc Engines

These performance gear sets are made for 125cc and 150cc GY6 4-stroke engines, the type usually found in full-size scooters and all-terrain vehicles. With several prepackaged gear ratios to choose from, you can adjust how your ride performs. They are one of the GY6 scooter parts that can meaningfully boost engine efficiency and output. Pick from several front and rear tooth pairings to match what you need.

Available Gear Pairings

The sets come with front tooth counts of 14, 16, 17, or 18, paired with rear tooth counts of 35, 36, 37, or 38. That range lets you set the ratio around whether you care more about top speed or low-end pull. The right pairing can help your scooter handle different terrain more smoothly.

Dimensions and Part Details

The small gear measures 60.5mm overall. The large gear has 19 splines, an inner diameter of 18mm peak to peak, and a thickness of 20mm. These dimensions are meant to suit most GY6 engine builds, so the sets are a practical option for riders who want to improve power delivery. For the best results, a big bore kit is recommended alongside these gear sets.

Specifications

• Overall Length: 60.5mm
• Number of Splines: 19
• Inner Diameter: 18mm
• Thickness: 20mm
• Fits: 150cc and 125cc GY6 4-stroke engines on full-size street scooters and off-road vehicles

Fitment

Fits:

• 150cc and 125cc GY6 4-stroke engines (full-size street scooters and off-road vehicles)

How to choose: Select your ratio by tooth count: 14F/38R, 16F/36R, 17F/36R, or 18F/35R (front teeth listed first, rear teeth second). Recommended with a big bore kit.

Shop more: GY6 Scooter Parts · Chinese Scooter Parts · Scooter Transmission & Final Drive · Scooter Engines & Engine Parts · Scooter Parts