moonframer

I have a 265 cu. inch stock 2- 4 barrel auto. I was trying to set the idle mixture on the primary carb and found it impossible to get any type of screw driver on the screws. There is no room to even get a flex screw driver to work. Also, do you need to set the idle screws on both carbs or just the primary? Any ideas please? Thanks, Jim

Frankie the Fink

I like to set up partial idle on both carb just to even out fuel distribution when idling. You can use a short 1/4" box end wrench to adjust the mixture screws or get one of these:

http://pitposse.com/po90de14inhe.html

Not cheap...but it sure makes life easier...

IF you have the ultra rare one year only real '56 carbs with the idle air bypass screw in the base....run that idle bypass adjustment all the way in until its seated and adjust the mixture screws as normally done on cars without the bypass..

waynec

Jim, I sent you a PM; I can email you a copy of a pub .

Its been many,many years since I fooled with those dual 4-barrels, my memory may be failing me, but I don't recall it being particularly difficult to adjust the fuel & air screws.
Seems to me I used small open-end wrenches at an angle from the sides for the fuel mixture screws, and a screwdriver for the air screws.

Use your imagination.
Something like these could work, even if metric, or could be filed to fit and/or bent to work:

Electronics supply stores may carry thin, long open-end wrenches with offset ends, likely metric, and could be filed & bent for easy access.
A miniature box-style gearwrench might also do the trick, since you only need to grasp the end of the mixture screw (but it would need to be a reversible ratchet if offset).


Wayne

moonframer

Hi Frankie, Thanks for your advise and link to this tool. I ordered it today and hoping it does the trick. Thanks again, Jim

Frankie the Fink

It works but withOUT any of the attachments though. The tool's mount for the attachments is actually a 1/4" socket - so you use it by itself.

The small Philip's head bit that comes with the kit is the shortest I've ever found; with a 1/4" box end wrench on it you can use it to tighten C1 turn signal bell housings that use that wedge fixture from the back and get things REAL tight....

The point of having both carbs contribute a bit to the idle is just to get that front carb's throttle plate a little off the fully closed position so it never sticks from sitting in that spot too long... Some drive like a Sally so it might never get moved off fully closed otherwise...

waynec

Jim, got your PM reply, but you didn't give me your email address.

moonframer

Thanks, thats interesting about the secondary idle. Jim