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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: 77 cc lb on December 16, 2010, 05:15:05 pm
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hey everyone, i have a 292-6 w/ a 1 barrel carb. when i start it up or put in park after driving it likes to rev high. i have only seen one adjustment screw on the front of carb. if i turn it all the way clockwise it starts to run rough and two turns cc it runs alright but still revs high. is it poss. these engines are high revvers? i don't know how many of you are exp. w this carb or engine, but any help or info would be appreciated. thanks
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vacuum leak check all you hoses for cracks
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Sounds like you are turning the mixture screw. There are two screws on the linkage near the throttle shaft. One is the fast idle adjustment screw for when it is cold. It contacts the throttle lever when the choke is on. The other is the base idle adjustment screw for when the engine is warm and the choke is off. The engine is supposed to run fast when it is cold but when the choke heats up and opens the choke plate it also moves the lever away from the fast idle adjustment screw allowing the throttle lever to rest on the base idle adjustment screw.
Make sure you do not have any vacuum leaks (Vac. hoses, carb base gasket, intake gasket etc.) and somebody has cranked up the idle speed to compensate for it.