Never noticed my Weber DGV do this before; when the idle mixture screw is turned all the way in, the engine still continues running. Shouldn't the engine die? Is there another path that the fuel/ air mix can be moving through when the car is idling? I hope the seat isn't damaged/ deformed, I don't know if I'll ever be able to get the engine tuned correctly then...

I believe jetting is overly rich at the moment; spark plugs are fuel soaked. I will be checking the jetting and mixture with my Colortune glass spark plug this week.

Just picked up the Hanynes Weber/ SU Carb manual, hope to gain more insight and figure out what's going on. Maybe it's time for an SU.

I've managed to get my Weber pretty nicely jetted (with the help of an air/fuel meter), but also haven't been able to get the idle quite as lean as I'd like. From my recent experience, if you are getting fuel-soaked plugs, I'd check your float/float valve- at one point in messing around my float stuck and resulted in soaked plugs.

I'm also thinking of going to a dual SU set-up, but waiting to see what John Parker at V-Performance unviels. He's hinted at a carb set-up in the works that will offer both better power and economy.
Tom
NYC

Well, I fixed a few problems. The float was off by 3 or 4 mm, and the fast idle control rod was bent in such a way, that the throttle valve was opening up too much when choke was applied. Don 't know if the extreme bend in the "S" shaped rod was affecting the throttle valve when I wasn't using the choke.

Going to double check everything after coffee and reinstall.

If you have the idle speed screw set too high, you'll get gas through the progression circuit. At a real idle setting, the progression holes are not exposed to vacuum and the ONLY way fuel gets into the intake is between the mix screw and its seat.

If something is holding the throttle open, the mix screw will have little effect. If the throttle is just barely cracked, like it should be at idle, you should be able to kill the motor with the mix screw.

Can the choke be stuck on, which would both richen the mixture and open the throttle beyond the normal idle position?

What model DGV is this. Its been along time since I owned a car that had a Weber. Mine had a 32-36 DGV. Choke on this model could be stuck causing an over rich condition. Haynes has a very good manual on the Webers, you might want to check it out. I would find it unusual that a standard Weber DGV would cause an overrich condition. Is this a new one or a used one. If used someone could have changed the jets. I believe there were many different jets available.

Thanks for your insight gentlemen. This is the manual choke 32/36 DGV.

Removed air filter assembly and looked at chokeplate, it's in vertical position when choke handle is pushed in.

One thing that may (?) be part of the problem is the little S shaped rod between the choke linkage and fast idle lever. Way back whenever, I bent the rod, in order to increase the idle speed when choke handle was pulled out. Seemed like a good idea at the time, and caused no ill effects on the other engine.

Now that the carb is on freshly rebuilt B20, I might have to rebend that rod so that the idle speed doesn't increase so much when choke is applied.

The tech dept at company where I purchased my performance jetting kit suggested that I check my float level also, I guess that could contribute to a flooding condition. I adjusted the thing real carefully when I rebuilt/ cleaned my carb, but I guess it wouldn't hurt doublechecking...

Sorry, but I now nothing about Webers. But this the first time someone has considered going from a Weber to SU's! Amazing!
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1985 240 DL 1967 122s Wagon

Not so... I've de-Weberized various cars. SUs can be very nice if they're not worn out.

I'm having my dual SU's rebuilt as we speak, should be fun once we get em' back on!
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1985 240 DL 1967 122s Wagon