Weber issues - need opinions

dlampe · #1 (**permalink**) 05-07-2006, 03:11 PM

When I rev the engine in the garage I have a pop in my sidepipes after about 2000rpm's. Maybe more on the driver side but the damn thing is so loud I really can't tell. What will cause this popping? I have sprayed carb cleaner around the intake but found no leaks. I think my fuel pressure is right at 2.5 and I think my timing is around 38 degs. This is a 408w.

idle jet 65
idle jet holder 120
primary jet 150
air correcter is 190
f7 tubes
50 exhaust valve and pump
37 venturi's

I am running rich around 11 to 12:1 A/F. That is not that far off. If that is the issue, what to change? That ratio is through the whole band.

The car runs pretty good already but I really hate to do to much road testing since it is not exactly legally registered yet.

Rick Parker · #2 (**permalink**) 06-14-2007, 06:41 PM

What did you determine was at fault?

dlampe · #3 (**permalink**) 06-15-2007, 04:13 AM

I went to f16 tubes and corrected some carb balance issues. I got your PM, just haven't had time to get back to you but the chokes are OEM.

JCoop · #4 (**permalink**) 06-15-2007, 05:49 AM

I assume you have 48 IDAs?

Popping usually means too rich; as opposed to sneezing, which would mean lean.

When this occured with my setup, I went lean on the idle jets (55s) and disconnected the distributor vacuum advance. Timed it to 38 deg. max and she's running great. Just a bit fat at idle but the transition is smooth and response immediate. You may want to go to the next smaller size idle jets, 60's maybe.

edit: This was on the GT40 w/ 302.