Dave, I have the same setup on my '79 Spit. I tend to idle cold about
400-500 (a little rough) but once warmed it runs very well at operating
temp, about 600-800 rpm. This is ideal. Why is your car idling so high?
do you have any other mods on it? The Haynes manual gives a very good
description on how to tune the carb. (Assuming nothing else is wrong with
it) Let me see if I can remember how to do it off the top off my head.
Bring your car up to operating temp. Ensure that your choke is open while
tuning your carb! Turn your idle mixture screw the entire way in and then
back it off a quarter turn. Slowly turn your idle mixture screw out until
your engine is running at the fastest RPM (if you continue to turn your
screw past a high rpm it is quite possible that the rpm will drop and then
come back up) Plan on your engine stalling a couple times. Once you reach
the highest rpm then readjust your idle screw to bring it back to a normal
idle. Then start adjusting your idle mixture again till you reach the
highest rpm, then again readjust the idle screw. repeat this process until
you are satisfied with your results. After you have finished this, let
your engine cool and do this process again. I hope it works out for you.
Patrick Bowen
'79 Spit
At 11:58 AM 7/22/98 -0400, Dave Simpson wrote:
>To: list
>
>
>I have a 76 spitfire with a weber down draft carburetor, K&N air filter
>and a set of exhaust headers. The car is seems to be running rich and
>using a lot of gas, the exhaust pipe is pretty blackwith soot.. Also
>the idle seems to vary with engine temp. Some days it idles at about
>1200 rpm, then the next day it will, after it is warmed up it start to
>idle at 1200 and then slowly drop down to 600-700 rpm. When you are
>sitting at a long light. Also the is little change in the way the car
>runs when adjusting the idle mixture screw. The screw seems to bottom
>out on the spring, if you remove the spring then it screws in a lot
>farther. This carburetor was disassembled last year, by me. Any
>tips but I take to a mechanic. TIA
>
>Dave Simpson
>NE OHIO
>
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