QMB139 Clutch Bell

If your 49cc QMB139 scooter squeaks, chatters, or grabs hard when taking off, the clutch bell is likely glazed. Replacing the bell and cleaning the clutch surface will restore smooth, quiet acceleration.

The Details

Glazing occurs when heat builds up inside the clutch bell, leaving a hardened, shiny layer that causes slipping, squeaking, and harsh engagement. Replacing the worn clutch bell gives the clutch shoes the correct surface to bite into again.

To restore the clutch itself, scrape the glazed layer off the clutch shoes using a razor blade — just like removing a gasket. This exposes fresh material and helps the clutch grab smoothly once the new bell is installed.

Important Things to Note

• Works on all 49cc QMB139 / GY6 50 scooters
• Inspect clutch shoes for uneven wear before reinstalling
• Avoid sanding — scraping keeps the clutch surface flat
• Check for heat spots on the variator and drive belt as well

What's Included

• Replacement clutch bell for QMB139 / GY6 50 scooters