Venturi Inserts ø 28mm Pair

Venturi inserts.
Diameter: 28 mm.
For Weber 40 IDF.
Sold per pair.

The air drawn in by the engine passes through the venturi into the carburetor - it is a kind of restriction in the carburetor. Through this restriction the incoming air flows faster, creating a vacuum. This vacuum draws fuel through the main jet and mixes it with air.

The venturi controls the sensitivity of the carburetor: the narrower the venturi, the higher the air velocity, and vice versa. A venturi that is too small leads to poor cylinder filling at high rpm, and one that is too large causes problems at low rpm.

These venturis are designed for the Spanish Weber IDF 40 carburetors and the American EMPI HPMX 40 carburetors.

They can also fit the Italian Weber IDF 40, but check the outer dimensions: diameter 40.9 mm, height 36.8 mm.