GY6 50cc (139QMB) Long Case CVT Cover Gasket

CVT Cover Gasket for 139QMB Long Case Engines

This gasket is made for the long case 50cc and 80cc 4-stroke engines, specifically the 139QMB design. It creates a seal between the engine case and the transmission housing, helping keep dirt and moisture out of the drivetrain. As with many GY6 50cc scooter parts, it is best to swap in a new gasket any time the CVT cover is removed for service, since reusing an old one can let contaminants speed up wear.

Long Case Compatibility

At 17 inches long, this gasket matches the long case version of the 139QMB engine, which is usually found on scooters with 12" or 13" rear wheels. The 10-bolt pattern is punched to line up with the factory mounting points, so it sits correctly and seals well when installed.

Material and Function

The gasket is built from an oil-resistant composite. When the cover is tightened, the material compresses slightly to fill small irregularities on the mating surface, giving a snug fit. It works as a barrier against dust, moisture, and road debris, which helps protect the variator, rollers, and other transmission parts over time.

Specifications

• Material: Oil-Resistant Composite
• Size: 17 inches length, 7 inches widest point
• Bolt Hole Count: 10
• Engine: 139QMB / 1P39QMB (Long Case only)
• Application: 50cc and 80cc 4-stroke scooters
• Fits: GY6 50cc and 80cc 4-stroke long case 139QMB engines (17-inch CVT cover, 10 bolts)

Fitment

Fits:

• GY6 50cc 139QMB long case engines (scooters with 12" or 13" rear wheels)
• GY6 80cc 139QMB long case engines (4-stroke)
• TaoTao, Roketa, Wolf, Bintelli, ZNEN, Jonway, Keeway, Vento (139QMB long case engines)

How to choose: Check your CVT cover. It should measure roughly 17 inches long and 7 inches across at its widest point, with 10 bolt holes.

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