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Default Title · 1200-4003

Chicago Scooter Company M12 Variator Nut for CSC go., 139QMB Scooters

Blue Line Variator Nut M12x1.25 - 139QMB Scooters

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Blue Line Variator Nut M12x1.25 - 139QMB Scooters

Name: Blue Line Variator Nut M12x1.25 - 139QMB Scooters
Brand: Blue Line
SKU: 1200-4003
Price: 1.00 USD
Availability: InStock

$1.00

Part number 1200-4003

Check dimensions and compatibility before ordering.

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Description

This Blue Line variator nut is an M12 × 1.25 replacement for a broad range of Chinese 139QMB-based 50cc and 80cc scooter applications. It secures the front variator assembly, making it a handy replacement during CVT service when the original nut is missing or damaged. The hex head and integrated smooth-base flange match setups requiring a 23.5 mm overall nut diameter and 8.85 mm height.

Features

Broad scooter compatibility: Suitable for matching 139QMB-based 50cc and 80cc configurations across multiple scooter brands.
M12 × 1.25 thread: Specific thread diameter and pitch for compatible variator-retaining applications.
Smooth-base flange: Integrated flange provides the required seating surface.
Hex-head design: Allows socket engagement during installation and removal.
CSC fitment: Also fits the OEM variator application on CSC go., go. MAX, Pug 50, and Nitro Sport 50 scooters.

Specifications

Brand: Blue Line
Part number: 1200-4003
Part type: Variator flange nut
Thread size: M12 × 1.25
Overall outer diameter: 23.5 mm
Height: 8.85 mm
Base: Smooth
Quantity: 1 nut

Model Fitment

For Chinese 139QMB-based 50cc and 80cc scooter configurations that use an M12 × 1.25 variator nut with matching flange seating and clearance. Fitment is based on the installed engine and variator hardware, rather than the badge on the scooter.

Application	Fitment details
Chinese 50cc/80cc engine configurations	139QMA, 139QMB, 1P39QMB, 1P39QMA-2, YN139QMB, JJ1P39QMB, 139FMA-2, BD1P39QMB, BN139QMB, and 147QMD configurations using the matching nut specification
Other QMA/QMB configurations	Confirm M12 × 1.25 thread, 23.5 mm overall nut diameter, 8.85 mm height, and smooth flange seating against the original
Chicago Scooter Company	go., go. MAX, Pug 50, Nitro Sport 50

Match the original nut and crankshaft thread before ordering. Install to the vehicle manufacturer's torque specification with the variator components fully seated.