Holley 1901 choke pull off is weak.
 

Have a 54 Meteor, which is a Canadian Ford with the 255 Merc flathead and the Holley 1901 2 bbl carb. Canada got the flathead one more year than the US in some models.

I actually have three of these blessed cars, and the one I'm having trouble with I just bought a week ago.

Engine runs beautifully, but the choke pull off barely pulls the choke back when it first starts unless you rev the engine or manually move the choke linkage.

I removed the whole mechanism from the side of the intake manifold and took it completely apart, It is super clean inside, no carbon, and all the pivots are freely moving. There is no apparent wear inside the "cylinder" for the little piston, and the piston looks real nice. I do not have a manual for rebuilding these carbs. The piston has two grooves, should there be o-rings in there? I suspect that would make a better seal but don't know if it should be like that. There is no vacuum leak, and I made a new gasket which is sealing perfectly. The vacuum does seem to just slip past the piston, I tried it with a vacuum pump.

Re: Holley 1901 choke pull off is weak.
 

Are you sure the vacuum channel that's drilled in the intake manifold is completly clear ?
The piston should be a good fit and slide freely, but not sloppy. No o-rings on the piston though.

Sal

Re: Holley 1901 choke pull off is weak.
 

I removed it again, and this time blew compressed air into both ports on the intake manifold. I got a lot of air through both. Will see how it performs on a cold morning.

Your statement about how the piston should fit well and slide freely, not sloppy is pretty accurate to how this one is behaving.