Small Frame Vespas have only two jets: a main jet that the needle passes through, and an idle jet.
Idle jets come in only two sizes: 42 and 45. Generally, Vespa 50 and 90 use a 42, and Primavera/ET3 use a 45.
Jetting is something that takes trial and error. See our blog of jetting instructions for more info.
Jet, Idle #42; SHA/SHB
Carburetor / Fuel System
Other products by
Have a Question about this item? Click here to email us.