3721SB AFB Rebuild Dilemma

[Stuart F.]

Now that new and improved Rebuilding Kits are available on the Corvette Parts market for Carter AFB Carburetors, I run into an unusual problem; For a number of years and with various Carb models, a Nylon or plastic shaft Accelerator pump was supplied in new or replacement units. These pumps have a fixed override spring assembled to them. The newer rebuild kits are provided with a pump having a brass shaft and no spring. You are expected to remove the spring from your old pump, which uses a slotted cup washer to retain the spring, and assemble it to the new pump.

Prior to my move from Illinois to Florida, I pitched out a lot of my old carb pieces and parts which leaves me with nothing to fall back on to replace this spring (I did find a couple of slotted washers in my hardware drawers). Needless to say, these pieces are not available separately from any retail outlet. My only options are to use the old Nylon pump, buy another kit or tear apart a perfectly good back up carb and strip it for parts.

Has any one else run into such a problem and, other than still being in possession of an old parts supply, how did you deal with it?

Stu Fox

[Stuart F.]

Re: 3721SB AFB Rebuild Dilemma

I guess no one else has had such a dilema. Does anyone have an old accelerator pump from an AFB in their junk box (complete w/spring) they can sell me?

Stu Fox

[Ken A.]

Re: 3721SB AFB Rebuild Dilemma

Email me & I'll give the parts for shipping

[Stuart F.]

Re: 3721SB AFB Rebuild Dilemma

Ken;

Thanks for the help. It worked like a champ.

As an update to others who have been fighting the "stinky AFB" problems, I've done the following and will post test results in a future thread:

I have rejetted my 3721SB back to 63 AFB Model 3461S specs, i.e. 16-389 metering rods, .104" primary jets, and I sweetened the secondaries to .070"s. I installed "Tomco" fuel inlet valves in place of the needle/seats, and set the float levels at 9/32" (instead of 7/32", measured from the top with gasket in place). The drop remains standard at 23/32".

My theory is that being as how the Tomco valves flow more fuel, I can get by with less fuel in the float chambers as my fuel make up will be better.

When I pulled off my backup carb (a 3720SA) that I recently rehabed to stock specs, I found fuel sitting in the manifold floor ribs under both primaries, and the car had been sitting for only 6-1/2 days. It is no wonder the auto parts store wouldn't accept my last drain oil as they said it smelled like gas. Therefore, it didn't matter which carb I had on the car, both were in top condition and set to standard specs - so I had to try something.

Stu Fox