3461S-Float Level Conflict

[Les Jacobs]

In the 1963 Corvette Shop Manual there are two conflicting float level specifications: On page 6M-5 of "Engine Fuel" it calls out 5/16" with the gasket in place (approximately 1/32 nominal thickness). On page14-4 of "Specifications"it calls for 7/32 withOUT the gasket. The difference is approximately 1/8 inch. So first question is does it matter? (off idle problem involved), and the second is of course, which one is correct? Thanks Les

[Duke W.]

Clem - this one's for you!!!

Hmmm, good eye. It's been to long since I rebuilt my AFB to remember how
I set mine, but my hunch is that the spec section is correct.

Note that the way float level is measured on the bench, the "larger" the measured setting the lower the fuel level in the bowl.

Hopefully, Clem will have an answer.

What was it set at when you disassembled the carb, and what is the nature of your "off-idle problem."

Duke

[Les Jacobs]

Re: 3461S-Float Level Conflict

Duke
My off idle problem is a low end (800-1200rpm) flat spot upon take off.(327/340). ( I posted the idle/off idle problem recently and you and I exchaged messages last week about the idle/off idle fuel flow thru the primary venturi). The float levels were grossly off (one hi, other low) when I first opened it up(many openings-I lost count), so I didn't record the initial settings . I have been using 5/16 when reassembling, so Im hoping that correcting the delta might fix the problem. By the way, carb now has correct rods, accerator pump (and setting), and most importantly proper metering rod springs. (the old ones were too stiff and it was way too rich). I am also using the Echlin 1810, and have checked the timing map (3 parts). It now runs almost great, but Im looking for that last 10%. Thanks Les

[Clem Z.]

Re: 3461S-Float Level Conflict

7/32" w/o gasket,3/4" drop and for the off idle try the idle mixture screws out 1/2 to 3/4 turns more. make sure that the idle transfer slot is not open too far,max .020, as you could be idling off of the transfer slot and when you open the throttle there is no extra fuel coming from the slot causing your flat spot.

[Les Jacobs]

Thanks Clem *NM*

[Gordon Peterson #4961]

Re: 3461S-Float Level Conflict

A discrepancy in my treasured '63 Shop Manual!?? Oh NO!! I grabbed my brown war-weary copy to make a correction in it. On page 6M-5, Step 6, I found 5/16" drill boldly X-ed out and a note to myself from way back in 1978 saying, use 7/32" drill w/o gasket. And I guess I'd have to recommend that setting because I haven't had to touch that AFB since. Still runs like new even today. Good luck!

Pete

[Les Jacobs]

Re: 3461S-Float Level Conflict

Clem I adjusted the floats and it cured the problem. Yippee! Its one of the problems (along with a dirty carb, and incorrect metering rod springs) that has dogged me for 6 months. Its still not quite right, but its close enough that Im not going to worry about it for a while. Thanks again. Les