Model A carb questions...

Hello Gents,

I plan to remove and clean my carb. It runs well but when stopping it becomes fuel restricted and occasionally dies. It indicates time for a good cleaning/rebuild. In this process I found my carb is one that had the manufacturer ID mold ground away. The result, as I understand it, is from a marketing dispute between Zenith and Holly. It was only manufactured from January to June of 1930. I plan to replace it with a Zenith #1 (which would have been stock for my vehicle) and was wondering if there are folks looking for this particular carb? I'm not sure this is the place to ask, so please accept my apologies. Thanks for any help/direction. -Den

 

try posting on "the Ford Barn"
maybe turn your GAV out to richen mixture
nice car good luck

 

Thanks. It doesn't appear to be a special carb. I've since learned Ford mixed vintages and suppliers to make use of inventory, etc. Sometimes engines were built many months ahead of when they were installed into a chassis, so model years can have different parts too.

 

could also be crud from the fuel tank clogging up the jets and fuel ports in the carb..I had that problem so I pulled the tank and got about 1lb of rust silt and petrofied gas gunk out of the tank plus a couple other goodies

 

I found the problem this morning. The GAV assembly has a small bend in it and was not operating properly. It must have been bumped/dinged sometime in the past. I am fortunate the fuel tank is very clean.

 

One of my A's has that problem, stop hard and she wants to die. Most of what I've read is its caused by too high of a float level, however I have tried the float too high, too low, set to spec, never have got it to go away! Hard to tell if its going lean, or going rich...I just drive it now

 

I chatted with a Model A owner that explained to me the cause is a vacuum leak at usually the flange gasket or butterfly valve bushing. I'm taking mine down for rebuild and I'll let you know the results here. He has a great tip to check for leaks, while its idling squirt a very tiny amount of starter fluid at the suspected vacuum leak spot. If the idle jumps up, the vacuum leak has sucked in some starting fluid. Increasing the GAV only masks the problem I guess.

 

Final results of the carb issue... I replaced my carb with a tight, fresh, rebuilt unit. It's almost like driving a different car. Stronger, smoother idle, no longer dies with hard braking. The old carb was just too worn out. It didn't have any large vacuum leaks, but it had many small ones. In combination with the worn adjustment needles, it was having a hard time metering fuel properly. While it may have been drivable before, the difference in performance is very noticeable. I think the reason this problem is sometimes difficult to diagnose is because it is the combination of several smaller things. Fixing just one of them didn't really solve the problem, but a fresh carb did. I went through all of the filters too inspecting for dirt and corrosion. Clean tank, clean filters, clean carb, good running engine.