Carb
Fleet Owner
Joined: Sep 2005
Posts: 28,609
Likes: 18
From: Lake Tahoe, Nevada
Posting Guru
Joined: Jun 2004
Posts: 1,635
Likes: 0
From: Niceville, FL.
The front idle mixture screws on my '83 F350 with Holley 4180 use a 6-point star (Torx?) wrench. My "parts" carburetor has plain ol' flat screwdriver slotted heads (but it was rebuilt at some point and the carb #s removed). My neighbor has an original off an E350 and it uses a Allen (hex) wrench. You'll probably have to use a mirror and a flashlight to see what you need. OBTW, I ended up at about 2-1/4 turns on right side, 2-1/8 turns on left side and about 1/4 turn cw from initial setting on curb idle screw for smoothest idle at specified rpm. I don't think you should ever have to go more (richer) than the initial 2-1/2 turns on the idle mixture screws. I can get a reasonably smooth idle with the mixture a little leaner but then I get a little acceleration flat spot under load from a standing start. I never removed or adjusted the secondary idle screws, just used cleaner and compressed air to clear the passages.
Last edited by Piffery1; Oct 17, 2006 at 04:32 PM.
