Holley 4000 Carburetor

Holley 4000Holley 4000 Identification – The
carburetor number is located on the back side of the carburetor on the face of the flange. There may be multiple numbers, but the important
one is the LIST number. I.E. LIST 1161.
Holley 4000 Rebuild DVDHolley 4000 Instruction Sheets

Holley4000 Visual Instruction Manual

Holley 4000 Carburetor Manual

Holley 4000 1955 Newsletter

Spring Loaded Needle & Seat

The type of needle & seat which works with the spring-loaded retention system is no longer available. However, the needles used in them are identical to those used with the threaded seat. Some kits contain instructions to simply use the new viton-tipped needle in the original seat and discard the new seat.What Does The Spark Control Valve Do?The spark control valve in the passage from the throttle bore provides an efficient degree of spark advance during periods of acceleration by momentarily providing a partially retarded spark. This partially retarded spark minimizes detonation, or pinging and increases engine responsiveness while accelerating. In effect, the spark valve provides an intermediate spark advance curve between a fully retarded spark and the normal spark advance which would be excessive when the engine is suddenly accelerated. The spark control valve accomplishes this by controlling the manifold vacuum admitted to the distributor vacuum line.

Removing stuck discharge nozzles.

Holley 4000
Refer to #30.
Please note before doing this that you can distort or crack the bowl housing. Take your time and be very careful. Grind the tip of a screwdriver tip to fit into the keyhole-shaped recess in the top of the discharge nozzle. Try to move the nozzle back and forth, but take your time with this. Any movement at all is a sign that they will probably come out if you work them long enough. Sometimes adding some heat will help. Now using a sharp blade or awl tip driven into them above the “duckbill”, as horizontally as you can, pry against the adjacent casting.


Holley 4000 Carburetor KitsHere are the various kits that we have for the 4000. There are subtle differences in the kits, so be sure to use the carburetor number and
match to the list contained in each carburetor kit.

Ford Lincoln 1956-57
1953-54 Lincoln
1955-56 Ford Lincoln
A customer reported a problem where the drivers side air fuel mixture screw didn’t change the engine speed. This was after the carburetor was rebuilt.

It is probably a vacuum leak due to a bent “boot” at the front of the bowl. You see, one side of that boot has a cast-in breech tube for the idle circuit (which recesses into the idle passage), the other does not — makes no sense whatsoever, but there it is. I’ll bet that it is the side without the breech tube which is causing problems. Put 1 or 2 more gaskets under the boot to see if that will solve the problem without lifting the front of the bowl too high to seal to the choke air horn. Using a very thin coating of Permatex Anaerobic Gasket
Maker around the gaskets’ passage holes can’t hurt, either.
Watch a video about the Holley 4000 Choke Housing
Watch a video about installing an electric choke
The needle & seat plug leaks fuel

Spread a thin layer of Permatex anarobic gasket maker on both sides of the gasket. This will help the gasket flow into the imperfections and seal.

Thanks for the advice about the Permatex anaerobic. Worked beautifully. Unfortunately, the carburetor still has a problem. At idle, if you look in the air horn, you can see fuel dripping down from the boosters. It did thisa before it was worked on and it still does it. The float level and fuel level in the bowl are exactly right according to the shop manual. The fuel pump pressure is 5 psi, which is the middle of the recommended range. The carseems to be idling on the fuel dripping down. The mixture screws can be turned all the way in and the car will still idle. At this point, what do you recommend that I look at? I am exasperated!

My first instinct would be to check the accel. pump discharge needle. It should be the longer (hence heavier) one, not the short one used in Holley 2100s (“Ford 94″). If it reaches almost to the top of its bore in the 4000, it is correct.

Next, I would seat that needle with a 5/32″ – 3/16” drift punch — a couple of gentle licks with a one pound hammer should suffice. If they aren’t seated, they leak.

All that I am left with is the possibility that the bowl is overfilling or that it is getting hot enough to percolate the gas out into the intake . . . but I am betting on it being the accel. pump needle.

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