You-All Carburetor (CV, 18mm, w/ Accelerator Pump); QMB139

This is a high quality 18mm CVK replacement carburetor for all GY6 4-stroke 139QMB 49/50cc Chinese engines. This carburetor is fitted with a #85 main jet. This is better than stock and comes with a larger venturi, an accelerator pump, and quality construction. This carburetor is used on Baja, JMstar, Jonway, Lance, NST, Peace, Roketa, Sunl, Tank, TNG, Vento, VIP and many others.

Mechanic's Note: This is better than the stock carburetor! It comes with an accelerator pump, which will frequently eliminates hesitation when you open her up.

This product is not intended for use on public roads or land.

Auto choke

Accelerator pump

Venturi: 18.5mm

Airbox side: OD 40mm, ID 35mm

Engine side: OD 28mm, ID 18.5mm

 

Jetting-

Main: 80 or 85 (4 mm thread PB)

Pilot: 35-38 (6 mm thread CV)

Needle jet: Non-adjustable JH 2mm thick x 43mm (tip to seat)

Compatible jets:

Main: PB style (JETKH1)

Pilot: CV Style