Originally Posted by Dajerseyrat
Back to the discussion about the carb that is currently on there...I checked how open the throttle plates are, and they are exposing well over .040 of the transfer slots. Im guessing the car is currently ideling off the powervalve or the main circuit causing extremely rich idle. I understand the principle involved in tuning the idle but with the throttle blades open less the car wont even idle to check the vacuum and adjust the set screws...Which leads me back to adjusting the idle set screw which reopens the throttle blades well beyond .040 and back to the beginning I go...
So, I have read on several tech articles that some guys dril 1/16" holes in the the leading edge of the throttle blades to let more air in, and allowing them to close the throttle blades within spec.
How do you guys feel about this trick??
Drill the blades as a last resort. To close the primaries more than they are now at idle, you should be able to add initial timing (which increases the idle speed). Once you get the blades closed down some, the idle mixture screws will work again. Use them to get the best idle, readjust the curb idle speed as needed while you are adjusting the mixture screws.
If you add initial you'll need to remove the same amount of timing from the mechanical advance.