GY6 50cc (139QMB) 69mm Valve Rebuild Kit

Valve Rebuild Kit for GY6 50cc (139QMB) Engines

This valve rebuild kit is made for 50cc 4-stroke QMB139 engines. It supplies everything needed for a full valve assembly, which can help restore performance and dependability. It is one of the GY6 50cc scooter parts we carry, and it plays a key role in keeping the engine running properly, supporting stronger compression and better efficiency. Replacing these components on a regular basis can head off larger engine issues and keep your scooter running smoothly.

What Comes in the Kit

The kit contains a full set of pieces, including intake and exhaust valves, a pair of valve springs, valve washers, seals, retainers, and keepers. Every item has its own job in the engine, together controlling the flow of air and fuel accurately, which is essential for proper combustion and engine output.

Signs It May Be Time to Replace Them

Think about replacing these valve parts if you notice lower power, odd engine sounds, or a general drop in performance. Keeping these components maintained helps prevent bigger problems later and keeps your scooter running efficiently.

Specifications

• Valve Length: 69mm
• Shaft Diameter: 5mm
• Intake Valve Diameter: 18.5mm
• Exhaust Valve Diameter: 16mm
• Fits: 50cc 4-stroke QMB139 engines (GY6 type), 69mm valve length

Fitment

Fits:

• QMB139 50cc/49cc 4-stroke engine (69mm valve length, 5mm shaft)

How to choose: Check that the valve length and stem diameter match your engine: 69mm length with 5mm shafts, with an 18.5mm intake head and a 16mm exhaust head.

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