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Author Topic:   rochester carb help
posted August 17, 2003 03:35 PM
i have the 1 3/8t inch the big one 76jets on a 355 chevit blubbrs really bad at idle to about 2500 rpms but runs great at 6000 what could be the problem it doesnt even want to stay running have to put it i low to get rpms higher to keep it unning during cautions also what do you set the float level to and the float drop

[This message has been edited by BK19 (edited August 17, 2003).]

posted August 18, 2003 06:10 AM
Assuming your idle circuit is set up correctly, you could have a stuck power valve, or just plain too rich a mixture due to the 76 jets. One other thing to look for is if there is a 1/8" brass tube next to the power piston it needs to be removed. It will pull extra fuel directly from the bowl in an unmetered way and can be some of the problem as well.
Also, the APT hole (Adjustable Part Throttle Circuit next to the power valve in the bottom of the bowl) will need to be blocked off with a small screw. That hole bypasses the power valve itself and can also be causing some of your rich condition.
These are just SOME of the things to watch for. Other things such as too small idle air bleeds could cause your rich idle condition because the condition seems to be going away after the main circuit takes over.

Hope that starts to help some.


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