OldIHC

I am trying to find out the original Holley 1904 List Number for a 1954 R100 - SD220 - 3 speed transmission. I have a couple of rebuilt carburetors that I have used, but the truck always dogs down and hesitates when you tromp the accelerator coming off of an idle. The truck does run ok and starts easy. The tune up specs are in line. Maybe the hesitation isn't necessarily a carburetor issue.
If I understand it right the list number refers to the jet(s) used in the carb based on altitude, transmission, serial number, etc. I checked the parts manual but didn't see any reference to the list number. Maybe this wouldn't change anything but for my own curiosity would like to find the original OEM list number.
Thanks. Great website full of information.

Off idle bog (the technical term for what you are seeing) is almost always a spark issue. first place to look is the vacuum advance, it is turning the whole distributor like it is supposed too, or did someone lock it down tight?

I should add, years ago I played around with jetting in a Holley 1920 (newer version of the same carb) and you could jump by many jet numbers before it would be a problem. I think I jumped from 32 to 26 before it got real noticeable.
As I said it is most likely spark, but low float level (effecting the hand-off from idle to main metering) or clogged passages, or valve timing all can cause it. You can check the "wet" float level (actual level of the gasoline in the float bowl) by removing the "economizer" from the top of the float bowl and inserting a 6" steel ruler, with the engine running. The economizer is the little cover on the top held down with 3 screws.
I don't know the level off the top of my head, and I would have to search to find a spec somewhere.

You should be able to find the list number here: https://www.thecarburetorshop.com/Truck ... tm#TkitIHC
The owner of the Carburetor Shop knows his stuff and has been very helpful to the IH crowd. Carbking on this site.

I is a fairly common "rookie " mistake to see the vacuum advance on these engines, that turn the whole distributor, as the distributor being loose and replacing the screw with the spring a washer with a bolt.
Also even if the correct set of hardware is on the distributor, is can get stuck in the block and not move with the vacuum applied.
Wrong jetting on the carb shows mostly at wide open throttle, that is when the pressure drop across the jet is at its maximum.
If fuel is the cause, which I doubt, it would be more likely from low wet float setting, causing poor "hand off" between idle and main metering systems.

According to Holley literature:

Sea level to 4000 feet - R-901-1A
Altitude - R-931-1A

Jon.

While I would certainly concur with Cornbinder that spark is the probable cause; improper idle mixture setting can also cause the bog/hesitation.

Too rich an idle setting will cause "puddling" in the intake manifold at idle. When the throttle is opened for acceleration, the greater air velocity in the intake sweeps all of these droplets into the cylinders causing an instantaneous over-rich condition and bog.

Idle mixture screw should NOT be out over 1 1/2 turns, and not over 1 turn for an engine with decent compression.

Jon.