Restore reliable fuel flow with this vacuum-operated replacement fuel petcock. Designed for scooters with gas tanks mounted high in the tail section, this petcock uses engine vacuum to open the fuel valve automatically when the engine is running — and closes it when the engine stops, preventing fuel from flooding the carburetor. Fits the M14x1.00 coarse-thread tank fitting used across CSC models and the broad GY6 / QMB139 Chinese scooter platform.
Key Features
Vacuum-Operated (Automatic): Opens with engine vacuum, closes at rest — no manual ON/OFF/RES lever required.
M14x1.00 Thread: Correct coarse-thread fitting for high-mounted tail-section fuel tanks on GY6 and QMB139 platforms.
5mm Fuel Outlet Barb: Standard barb size for OEM fuel line connections on listed scooters.
Integrated Filter Tube: Clear 62mm filter tube screens debris before it reaches the carb.
Compatible Models
CSC go. and go. MAX
CSC Bella Classic 50
CSC Nitro Sport 50
CSC Pug 50
GY6 125cc / 150cc scooters (157QMJ-based) with vacuum petcock
QMB139 / 139QMB 50cc scooters with vacuum petcock
Technical Specifications
Thread Size: M14 x 1.00 (coarse)
Nut Inner Diameter: 13mm
Fuel Outlet Diameter: 5mm
Filter Tube Length: 62mm
Operation: Vacuum-operated automatic petcock
Manufacturer: Prima / OEM | SKU: 129-25 / 164-93
Important: Compare your existing petcock to the image before ordering — once fuel has passed through this part, it is non-returnable. This petcock does not fit Genuine Scooter Company models, which use a different thread pitch.
