Bill, when you fiddle with the mixture you need to start the car and run
it until the carb is hot, the engine temperature should be in the normal
range. Then turn the idle mixture screw all the way in, don't tighten
it. Then screw it out, the engine should pick up RPM as you turn it out.
As you continue to turn it out at some point the engine will lose RPM.
Now you know the maximum and minimum setting. The object is to set the
screw so the engine is at the maximum RPM at idle which will be somewhere
in between the two maximum and minimum settings you have found. Once you
have done this you will probably never have to mess with it again.
After you have accomplished this you can use the idle speed adjustment
screw to sthe the idle RPM. If you have a standard cam in your engine
you should be able to set the idle somewhere between 700-900 RPM.
Larry Hoy (MGB.Roadster@juno.com)
Denver, CO USA
1969 MGB Roadster
1987 Jaguar XJ6 Vanden Plas
===============================
On Mon, 15 Dec 1997 12:21:58 -0800 bill <pplusb@northlink.com> writes:
>My '77 rdstr has a downdraft Weber.
>At a stop, it may idle straight down to zero and stall, or it may hang
>on to an idle for a short while before nose diving.
>I've fiddled with mixture, although not too expertly, and have the idle
>screw turned way up, to no avail.
>This phenomenon can be more pronounced when cold.
>I need help - anybody have any ideas??
>
>TIA
>Bill
>
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