65 289 carb question Please

I have a 1965 Mustang with a stock 289. I just installed a new Holley 2 barrel model 350. I went with a manual choke. My problem is that the idle is running at 1200-1500 rmp. I turned the curb idle screw completely out and it makes no difference still 1200-1500 rpm. I have tried different scenarios, warm motor, cold motor, and with the throttle plate in various and in its appropriate position. So my question is what would cause the idle to rev so high with the adjusting screw turned completely out.
I appreciate any input anyone can give, I am at a standstill....
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SN Certified Technician
Apr 12, 2002
make sure the fast idle cam is in its lowest position when the choke is open. also make sure the speed screw for the fast idle is set properly as well and isnt affecting the idle speed when the choke is open.
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Update: I got an electric choke and have the car running,
Last Question: The high idle screw on the holley 350 is to the rear pass side of the carb. Does turning the adjusting screw clockwise or counter clockwise decrease the high idle speed. Another way to put it, is it set up the same as the curb idle screw. c/w to increase & ccw lower.
Everyone has been very helpful and I do appreciate it
I just found out what the problem was. I pulled the carb again and found that the tab that rests against the idle cam was bent and not making contact with the cam, thus not releasing from high idle. Problems seem so simple once you find the answer.
Thanks to all for your reply's