honeylocust5

As per the advice given upthread, I pulled the venturi plate out last night, spent maybe 5 minutes filing it. It took longer to remove the cotter pin and tap out the pivot rod than the actual repair. The main source of the binding was along the flat end of the plate, closest to where it pivoted on the rod - that edge demanded more filing than the curved lip of the plate. I repacked the gas needle, and installed the carb this morning. The car started effortlessly. After it warmed up, I dialed in the gas and air knobs and each were less than 1/2 turn from the base setting to get the car idling smoothly with no choke. Incredible - what a difference. Thanks to everyone who offered advice and the detailed rebuild guidance.

I pulled the carb off this afternoon and you (and others above) were right on. The venturi plate rests 1/4 inch off the throat of the body. Clearly some expanded potmetal. I am all too familiar with that problem but had no clue this was a thing in this particular instance. I can fix Bosch K-jet injection in my sleep but was utterly befuddled by a Marvel updraft! I snagged some faucet packing at the store too and am excited to see how it goes. I will follow your guide and report back shortly. Thanks again to all.

Mark, and all, thanks for the great info. Going to check this today. Dumb question - where do I find replacement leather for the gasoline screw seal? I searched for replacement packing and see many options, but not leather. Is one of the other types a viable substitute? Thanks again!

Hi all, I recently started a 1926 Buick Master 6 after it had sat for 7-8 years. Before this recent start-up, I pulled the carb off, soaked it in carb dip, ran carb cleaner through all passages and reassembled. I set it per the instructions in a Dyke's book: air screw (big knob) parallel with the tang/spring and the gasoline screw (round knob with notch at bottom of carb) turned out 1.5 turns. The car runs well, but only at about 1/3 to 1/2 choke, even when warmed up, and in a very narrow range of choke engagement. It won't run at all with choke in, or out past 1/2. The puzzling part, and why I'm seeking advice is that adjusting these screws do... almost nothing. Slowly adjusting the gasoline screw in or out seems to have zero effect, same with air screw. The gasoline screw also has a very slow drip from it. Related? Any help is greatly appreciated!