This carb came stock on a 351 in an '87 E350, now on a 460 from an '85 E350. It was made by Holley for Motorcraft. It has recently been rebuilt, and now needs adjustment. Just one (of many) problem, I can't find the idle mixture adjustment screws. I have the Haynes Techbook for Holley carbs, but there is no screw where they show it. Best I can tell, it is supposed to be on the metering block (that plate beside the float bowl??). Can anyone tell me where to look? While I'm asking, might as well find out where the idle speed screw is also.
It's killing the gas milage (about 6 instead of 11). Actually, a complete adjustment proceedure, when you don't have a tachometer or vacuum gauge, would probably help.
Thank you to anyone who can help.

AWOL

 

It sounds as if someone has swopt some parts. If that is not the case and the adjustments are not there try this. On the base plate on the front are there two round plugs? If so you have to get the plugs out to get to the adjustment screws. You get the plugs out like this and don't be scared...first get a drill and with a small (about
1/8 inch or smaller preferably a little smaller)drill bit. Flip the carb upside down. Now in line with the plug go back into the base plate about a 1/4 of an inch and drill down a little then out towards the plug.You will be able to get between the adjustment screw and the plug. Now take a punch and drive the plug out. Don't go the other way cause A)the plug is solid B)you could go too far destroying the base plate.If you do not have the plugs in the front,get the list number from the air horn and visit the Holley website. I have written them before and they ID the carb and what to do.
The idle speed adjustment is on the side of the linkage under the kick down arm.
And setting the mixture is the easiest part. I don't use any equipment except my ears. All you have to do is turn the crew in until the engine starts to idle down then start backing it back out until the idle gets to it's highest RPM. Then stop and turn it a 1/4 of a turn back in. Repeat for the other side. Turn in lowest idle. back out to fastest and back in 1/4 of a turn. Hop[e this helps.
Dave

 

I'll try looking at that, if I can get to it, this Saturday (also got a junk car that needs a timing chain & cover *sigh*). I'll let you know what kind of results I get. Thanks again.


AWOL

P.S. What is the address for the Holley sight?