Weber 40's run way too rich

jimmcd · 10-26-2000, 09:27 AM

I have a 2.2ltr with dual 40IDF's. The car has run rich since installing the carbs (I know, FI is better).
I tried adjusting and cleaning out the carbs and put in hotter plugs as suggested by a friend, but it still runs rich. Way rich.

Jets are 1.55 Main, 2.00 Main A/C, .55 Idle, and f11 emulsion tube. I'm told the car should run fine with this set up.

I have an MSD6a w/ petronix, 050, MSD coil, and Bosch Platinum plugs. Compression is good.

The car actually runs great, but I smell like gas everyday and am afraid the rings will be shot in no time. Any thoughts would be appreciated

John Rogers · 10-27-2000, 05:51 AM

Check the float level setting on each carb. Sounds like the needle is not closing off the fuel supply when the float bowl gets full? Good luck.

jimmcd · 10-28-2000, 08:51 AM

I adjusted the floats, checked the fuel pressure, and it still runs rich. What about going to smaller jets?

MJHanna · 10-28-2000, 02:20 PM

I would change the idle to 50s first. You are running around town on the idle current 85-90 % of the time. 914s don’t like the cheap platinum plugs, go with the copper based plugs. I know you checked the fuel pressure but do you have a regulator inline?

jimmcd · 10-30-2000, 11:02 AM

I put in 50's for idle jets and switched back to Bosch Supers. It still ran rich. BTW, the mains are 115's not 155's. Venturis are 28mm. I have a regulator in-line and adjusted to 2psi.

It still ran rich until I adjusted the Accelarator Pump. I backed it off to the end of the adjustment post and the puffs of black smoke subsided. Problem is, so did the throttle response. Anyway, I adjusted it back in and have found a happy medium, although it still smokes at idle and to a lesser degree when going through the gears.

With that jetting, I still can't figure out why it doesn't burn all the fuel. At least it is drivable now. Any further suggestions would be greatly appreciated.