Dellorto VHST Pilot Jets

The Dellorto pilot jet changes the mixture at idle speed up to about a 1/4 throttle openings.

The most popular size pilot jet for trials bikes in the UK is around a 35, warmer climates or higher altitudes have less oxygen in the air so require smaller jets.

Fits VHST Dellorto Carburettors

The S style jets developed for use with the 2 stroke bikes, they have smaller holes in the atomiser tube that let less air through than the U type, this gives a slightly richer mixture.

The U style was developed for use with the 4 stroke bikes (although it can happily be used in a two stroke), it has larger holes in the atomiser tube giving a slightly weaker mixture. The U jets give a similar mixture to a S jet of 2 or 3 sizes smaller.