Moturo Starter Clutch Sprag for 139QMB QMA GY6 50cc

Moturo starter clutch for 139QMB QMA GY6 50cc

The Moturo starter clutch for your scooter with a 139QMB/QMA GY6 50cc engine — the first part to replace if you hear clicking noises during starting. Sits between the starter motor and crankshaft, protects components during speed spikes, ready for installation.

The starter clutch, also known as the freewheel, sits between the starter motor and the crankshaft. If the engine speed exceeds the starter speed during the starting process, the freewheel disconnects, protecting the starter pinion and crankshaft flange from damage.

Clicking or grinding noises when starting are the typical symptom of a worn-out starter clutch. Replacing it prevents consequential damage to the starter system and restores a smooth starting process.

Can be replaced in about an hour using a hex key set and a socket wrench set.

Starter clutch for your scooter with GY6 50cc, made by Moturo.

Performance · Material · Facts

• Sits between the starter motor and crankshaft
• Disconnects the starter pinion when the crankshaft speed spikes
• Symptom of wear: clicking noises during the starting process
• Fits scooters with a 139QMB/QMA GY6 50cc engine

Important notes – please read

Original spare part design, no separate ABE (general operating permit) required. For Chinese GY6 platforms, component versions vary within the same engine code — compare the outer diameter, mounting geometry, and gearing with the product image before ordering.

Tools & time required

• Hex key set in common sizes
• Socket wrench set for the mounting bolts
• Torque wrench
• Approximately one hour for an experienced mechanic

Scope of delivery

1 × starter clutch. Not included: alternator cover gasket, bolts, tools.

Frequently asked questions

Does the starter clutch fit all 139QMB/QMA engines?
The vast majority. Compare the outer diameter, internal gearing, and mounting geometry with the product image before ordering.

What symptoms does a defective starter clutch show?
Clicking or grinding noises during starting, starter motor slipping without cleanly engaging the crankshaft.

Do I need new gaskets for the replacement?
Recommended. The gasket on the alternator cover should be replaced every time it is opened.