BG Speed demon problems

I have a speed demon 650 carb on a ford 302 and i have been having a lot of trouble. most of the kinks have been worked out but i can't get it to return to idle, the secondaries are sticking slightly open, any ideas????


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If memorey serves I had a issue like that with my demon as well. I removed the carb, flipped it over and found where it was sticking. I found the butterflies were hitting high spots when they went into the closed position so I gently sanded the high spots out and didn`t have any problems since.

Look on the drivers side of the carb, you'll see a piece of wire linkage that goes from the main throttle arm to the secondary throttle shaft.

On some of these carbs even the full mechanical that piece of linkage is too long and it binds the secondary throttle shaft and causes it to hang open.

Check that linkage to be sure it's not binding.

Also check that same piece of linkage to be sure it's tight against the slot and pushing the secondary's all the way closed, it needs to be touching the end of the slot when at idle.

You also may want to check and see that the butterfly's aren't binding in the base plate.

Carb Adjusting 101.