CV40 Carburetor Vacuum Piston Assembly Diaphragm Plunger for Motorcycle Carburetor Repair

The CV40 piston assembly is a key control part inside motorcycle carburetors. It uses engine intake vacuum to move the vacuum diaphragm and piston up and down, automatically adjusting the air passage size and fuel supply ratio, which affects idle speed, acceleration and high-speed performance.

After long use, the original carburetor vacuum diaphragm may become aged, cracked or lose elasticity, while the piston may stick due to carbon deposits or wear. Common symptoms include unstable idle, sluggish takeoff, delayed acceleration, inconsistent high-speed fuel supply, backfire or increased fuel consumption. The CV40 piston assembly can directly replace the aged piston and diaphragm structure, restoring the carburetor’s automatic metering ability and helping the engine obtain a more stable air-fuel mixture at different speeds.

Suitable for repair and replacement of corresponding CV40 carburetors, it is a commonly stocked carburetor part for motorcycle repair shops, workshops and cross-border sellers. During installation, it is recommended to also check the fuel needle, jets, float chamber seal and intake pipe condition for more stable repair results.