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Old 05-31-2010, 02:45 PM
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Originally Posted by F-BIRD'88

On some Q jets there is a hot idle AFR conpensation air valve (bi-metal flat spring covering a air port) at the back of the carb body that opens up to allow more idle airflow to increase the engine idle speed and lean the idle AFR when the carb body gets too hot and over rich. (prevents hot engine over rich stalling) If this spring valve is stuck or broke off the port will be uncovered and the idle will be high even with closed throttles.
My Q Jet is a 1977 model. I don't know if it has AFR compensation air valve or not. Does any one have a photo or link so I can see what this looks like?

I did notice two V cuts about 1\16" deep on each primary butterfly. It looks like some one took a triangle file and made these cuts. This would increase air flow and raise idle speed even with butterflies completely closed. Maybe this is what is causing my problem? Why would some one make V cuts in butterflies????

So how do I fix the V cuts; install new butterflies, fill the V cuts with solder and file smooth? Any one know where I can get replacement butterflies? I checked Summit Racing and Edelbrock and they do not list them. I suppose I could get a parts carb at the next swap meet?

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