What is the float adjustment on a carter AFB 3720

[Chester C.]

What is the float adjustment on a carter AFB 3720. The dimension when floats are closed and open, thanks

[Michael G.]

Re: What is the float adjustment on a carter AFB 3720

Should you have a GM Service Manual for your car believe the information (spec) can be found under Carburetor. Most Carter Carburetor rebuild kits come with different width gauges to aid in setting the float levels as well.

[Timothy B.]

Re: What is the float adjustment on a carter AFB 3720

Chester,

I believe the float height is set using a 5/16" drill bit. The float drop is 3/4" but double check in the archives or like Mike says above.

[Edward J.]

Re: What is the float adjustment on a carter AFB 3720

Chet, I would subtract a few 32th's from the factory setting if you are using the 10% ethanol gas in your area. Its seems every time I set up the Carter carburetors to factory spec.s I got some overflow when the engine get's hot.

[Chester C.]

Re: What is the float adjustment on a carter AFB 3720

Chester,

I believe the float height is set using a 5/16" drill bit. The float drop is 3/4" but double check in the archives or like Mike says above.

That's what my manual states for the 3761S carb but I did not know it would be the same for the 3720. Thanks I will go with that.

[Stuart F.]

Re: What is the float adjustment on a carter AFB 3720

Believe you mean the model 3461s (not 3761). The factory settings for all Corvette 3460 series and 3720 series carbs are the same, I.e. 1/4" float level and 3/4" float drop. Using the 5/16" drill would actually be the first step towards dropping the float setting if you have trouble with ethanol laced fuels, like Tim posted. It works for me very well using Tomco fuel inlet valves, but not as well with standard needle/seats.

Stu Fox

[Stuart F.]

Re: What is the float adjustment on a carter AFB 3720

Actually, I think some specs say 9/32" on the level. Either that or the 5/16" drill is a step in the right direction these days.

Stu Fox

[Chester C.]

Re: What is the float adjustment on a carter AFB 3720

Believe you mean the model 3461s (not 3761). The factory settings for all Corvette 3460 series and 3720 series carbs are the same, I.e. 1/4" float level and 3/4" float drop. Using the 5/16" drill would actually be the first step towards dropping the float setting if you have trouble with ethanol laced fuels, like Tim posted. It works for me very well using Tomco fuel inlet valves, but not as well with standard needle/seats.

Stu Fox

Do you know the part number of the Tomco valve.

[Stuart F.]

Re: What is the float adjustment on a carter AFB 3720

The Tomco inlet valves of late are included with some of the rebuild kits offered by Corvette parts vendors. I believe the last kit I bought from Eckler's included them in place of standard needle and seats. I'm not sure who makes them now, but the quality is not what they used to be when manufactured and sold by Tomco. They used to be made from brass, but lately they are of some kind of pot metal and they are prone to breaking easily. This is critical because you tighten them with a socket (not a wide blade screwdriver). It is too easy to over tighten them and break them off. Otherwise, they work as well as the originals from back in the 70's and 80's. I recall that some vendors now handle the entire kit from Tomco, so obviously someone now owns the name and are trying to market the kits using the past reputation of the original Tomco brand.

Stu Fox