Twin IDF 40s

FrameShift · Post by **FrameShift** » Thu Jun 14, 2007 11:53 pm

Hi, Everyone,

Could someone give me a good starting point for the jetting for Weber twin IDF 40s for a 1979 1995 cc California specification, please? The carbs are the older types 11 and 12, I think. The car had all of that emission control stuff, which I have removed. Anything else I should be aware of for converting?

Cheers,

Brian.

TVST*R · Post by **TVST*R** » Sun Sep 16, 2007 11:46 am

You waited all summer and no response...
We suck!

All I can say is some day I hope to have twins!
T

Danno · Post by **Danno** » Mon Sep 17, 2007 9:57 am

TVST*R wrote:You waited all summer and no response...
We suck!

All I can say is some day I hope to have twins!
T

Haha, I was thinking the same thing. There are several of these unanswered posts out there. Hopefully people found some answers on the other fiat sites (the ones that aren't as easy to navigate).....

Danno · Post by **Danno** » Mon Sep 17, 2007 10:04 am

in case anyone cares I'm seeing several setups that have 125 (or 120) on main jets and 55 on the idle jet. One guy suggested going as high as 155 for the main, because of a flat spot he was noticing in power. don't know if that will help or not, but it's a start, right?

So Cal Mark · Post by **So Cal Mark** » Mon Sep 17, 2007 10:41 am

your question may have not contained enough info about your engine setup; so the answer may have been too vague to be useful. Is your engine stock? cams?, compression? exhaust? head work?

Danno · Post by **Danno** » Mon Sep 17, 2007 10:56 am

So Cal Mark wrote:your question may have not contained enough info about your engine setup; so the answer may have been too vague to be useful. Is your engine stock? cams?, compression? exhaust? head work?

yeah, the info I got was from guys who had stock 1800 engines and they were running 32 venturies...

mdrburchette · Post by **mdrburchette** » Mon Sep 17, 2007 7:58 pm

I'm running 125s in my modified 1608. 130s were too rich. The stumbling may be due to the bleedback jets. Here's a setup for a 2L that Jeff Scheferman recommends:

Assuming you have made no other performance mods, I would start with the following:

130 mains (you will probbaly end up with 135s)
55 idles
190 airs
200 needles
32 chokes
4.5 aux venturi
55 bleedbacks (35s if you get a stumble on accelerataion)
50 pumps
F11 emulsions

Be sure they are balanced and tuned correctly. Let us know how it works.