Weber Tuning

Jay,
here is a very quick rundown of the workings of the Webers:

Idle & transfer & the cruising is done on the Idle circuit. So its important to have this right.

The Idle jet consts of the Idle jet and the idle holder wich has the idle air bleed.

The bigger the idle bleed the more it will lean out at the top end, before the mains kick in..

The idle screws schould be out no more than 1 turn.

The main circuit consists of the main jet, the emulsion tube and the air corrector.

The emulsion tube will define when the main circuit kicks in.

The air corrector is responsible for leaning out at the top end.

There is about a 4 to 1 relation in sizes for the main jet to air corrector.

If you want, I can send you the original tuning guide as a pdf. Send me your email.


Your setup could be on the lean side if you idle holder is the standard 120. I have 65 with a 110 Holder

Also check if the 3rd transfer hole has been drilled (behind the brass screw)

The main is richer than mine - probably ok because your bigger venturis will have less of a "signal"

F7 is the same emulsion tube I am running

Your air corrector is much bigger than mine (120) you may want to check for excessive leaning at the top

Mike (Germany)
68 GT500