Upjet

From MopedWiki

Upjet is a term describing the action of changing the size of the main jet in a moped's carburetor to a larger one. This can be done either by drilling/boring out the existing main jet or by purchasing a new main jet from moped parts suppliers.

For Bing and Dellorto jets, the smaller the number (size), the smaller the hole. Upjetting will require a jet with a larger number (size).