Carb jet sizing, input needed Options

[dfelz]

I have dual webber 40 IDFs I am in the process of rebuilding for my 1911cc engine. One of my idle jets needs replacing and since i am order one i wanted input of sizing, to see if i should change the other three as well. I looked at a sizing chart and factory is a 28 venturi with 1.15 main and .5 idle. I have 30 venturi installed, so that means more air flow, which should also be accompanied by more fuel flow to stabilize the ratio. I was thinking a 1.30 main and a .55 idle...... want your input.

ALSO, i am either ordering from cb performance or aircooled.net, unless someone else has other sources.... but when i was comparing the prices, aircooled is over double per jet... but they do state that their product is NOT from china, and cb doesnt list a supplier..... anyone know if cb's are china products???

Thanks!! (IMG:style_emoticons/default/beerchug.gif)

[michael7810]

My 1911 has 50/135s and runs good. I've tried bigger idles and it runs ok but the fuel mileage dropped from 25 to19. I've found it will run good on smaller idles as long as sync timing idle speed are right on. My AF is 12.7 (idle) 15 (highway no hill) and 13.5 WOT. I have a local tuner shop that sells jets for $7.50 and let's you exchange for different sizes for free