GY6 50cc (139QMB) Intake Valve 69mm for 50cc 4-Stroke

Replacement Intake Valve for QMB139 50cc Scooters

This intake valve is made to swap in for a worn or damaged part in a QMB139-powered 50cc scooter. It measures 69mm overall, with an 18.5mm head diameter and a 5mm shaft diameter, matching the factory dimensions used on standard 49cc/50cc 4-stroke horizontal engines. It belongs to the group of GY6 50cc scooter parts that help keep the engine running as it should.

How It Works and Fitting

The intake valve controls when the air and fuel mixture flows into the combustion chamber. With age, this component can wear out, which may show up as lower power or misfiring. Swapping it out is a straightforward job for anyone comfortable with basic scooter upkeep, and it lets the engine return to smooth, efficient running.

Signs It May Need Replacing

A failing intake valve can cause weak acceleration, odd engine sounds, or trouble starting the scooter. If any of these appear, check the valve and replace it if needed to bring the engine back to good performance. Routine inspections can catch problems early and help the scooter stay dependable.

Specifications

• Type: Intake Valve
• Head Diameter: 18.5mm
• Shaft Diameter: 5mm
• Overall Length: 69mm
• Engine Compatibility: QMB139 49cc/50cc 4-stroke horizontal
• Fits: QMB139 49cc/50cc 4-stroke horizontal engines (GY6-style) on Chinese-made scooters

Fitment

Fits:

• QMB139 49cc/50cc 4-stroke horizontal engine (69mm overall length, 18.5mm head)
• Various unlisted makes and models using the QMB139 engine platform

How to choose: Confirm the engine is a QMB139 49cc/50cc 4-stroke horizontal, and make sure the valve is 69mm overall with an 18.5mm head and 5mm shaft.

Shop more: GY6 50cc Scooter Parts (139QMB) · GY6 Scooter Parts · Scooter Cylinder Heads & Valves · Scooter Fuel System Parts · Scooter Parts