The LLVR “Venturi” Air Intake System can boost the power of Vespa large-frame engines with SI carburettors by 1.5 to 2 PS compared to the restrictive original Air Filter.

Compact aluminum Air Intake System with Venturi effect and securely enclosed screw. It fits all SI carburettors with diameters ranging from 20 to 28 mm and provides a noticeable increase in power compared to a standard Air Filter. The engine responds much better.

• Compact design; fits under all Airboxes as well as under original PIAGGIO Carburettor Casing Caps
• Fits all SI carburettors from 20 and 24 to 28 mm thanks to the slotted hole for the idle screw
• Durable aluminum material, black anodized

The LLVR Air Intake System comes standard with a 24 mm diameter. The hole for the idle screw is pre-drilled to fit right out of the box and is also suitable for 26 mm and 28 mm SI carburettors. The inner diameter can be enlarged from 24 to 26 or 28 mm using a file and a Dremel. SI 20:20 carburettors taper toward the top and also have a 24 mm diameter in that area.

The Venturi fits the low-profile T5 carburettors from DELL’ORTO with the designation letter “G” if recesses for the Float Chamber are cut into the back. The LLVR venturi does not fit SI 27:23, 20:17, or 20:15 vintage carburettors.

Note: Replacing the standard Air Filter with the Air Intake System Venturi reduces the vacuum in the intake system. This indirectly makes the carburetor mixture leaner. The carburetor jet settings should be checked. Often, it is sufficient to unscrew the idle mixture screw further. Sometimes, the Main Air Correction Jet must also be selected 10 to 20 sizes smaller. The Main Jet can then usually be kept as is.