Hey dear Slant Six member I have changed my 1bbl 225 to a Super Six setup. And I took my Carter BBD (Chrysler 1974-84) that came from a 318 and I rebuilt it with parts from Mike's carburetor. The problem is that the idle is too high maybe 900-1000 rpm and I can't make it less. I have checked for vacuum leak twice with brake cleaner and that's not the problem. The idle quality is good and it has power all the way thru when I drive. The throttle valves are shut and I have the throttle stop all the way out. The idle screw setting is 1.5 turn out. Have checked timing and that's good, changed from points to Ignitor yesterday and still it got "high idle". The vacuum advance works too. Can it be something internal in the carburetor that make the idle to high? In the beginning it got a little flooding problem but that was due to a faulty installed gasket on the venturi cluster. The brass float floats. Have set the float little low just for it not should flood. Have adjusted the step up vacuum piston with no cange in idle. Does any one had any idea since it feels like I have tested everything for a week now.



Thanks

not sure why this hasn’t been answered, or if you are still looking for answer. Have a look at the 2 butterflies. The 318 carbie has holes in them that the 225 doesn’t. You will need to block off these holes to make it idle slower

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1967 VC Valiant