ive tried opening the rear throttle blades on the 750 hp carb. this has not helped my rich condition at idle. i have also went to a 3.5 power valves. timing is 36 total. air srews are out 1.1/4. IF i drill the throttle blades and this "IS NOT" the problem with the idle circuit, will i have destoyed the carb? thanks Dave

I'm gonna guess that no, you haven't destroyed the carb. I bought a 950HP that came with holes in the throttle blades. My motor surely doesn't need it. I have a very mild cam and tons of vacuum.

I'd make sure that you really need to drill the blades before you do so but you can still use the carb after it's done. I've got mine idling fine with the holes.

Tim.

You could also fill the holes with jb weld if you need to. I did on a carb that I had and it lasted for a couple of years.

Danb

You can use J B Weld or solder. I have used both with good results.

The only time you drill the throttle blades is if you have maxed out the idle screw on both primary and secondary, uncovering the transfer circuit and fuel is pulled from the boosters at idle, which makes for a real lazy rev and inconsistant high idle. Drilling the blades allows you to move more idle air with the throttle blades flat as possible, so you dont pass the transfer curcuit. High duration cams usually need the mod to idle.

A rich idle is ussally jetting, P.V related, airbleeds ect.