Anyone have any info on a 3759s AFB? I can't find it listed online by size or application.
It only shows up as 'this kit fits that carb'.
It may be marine application, and it has vacuum secondaries instead of air doors, which I haven't seen before.
The venturis look small, but I don't want to guess at the cfm rating.

Any ideas?

_________________
O==\=/==O

"A mechanic is Somebody."
- Jim Preston

Post some pictures.

Richard

_________________
Part of Tyrde-Browne Racing

The vacuum secondary WCFB's and AFB's were a pain in the butt. Carter discontinued them a long time ago.

If you've actually got a vacuum secondary AFB, put it in a museum. They only built them for a couple years. It's a lousy carburetor. Not worth the trouble of rebuilding in my book.
The air valve AFB is far superior.

2¢
CJ

_________________
Part of Tyrde-Browne Racing

Does it have air valves inside the secondary throat? AVS has one on top looking like an extra choke plate. AVS is spring controlled, AFB's have counter weights.

Chances are this carb would be a good size for a slant.

_________________
'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

It is an oddball, to be sure.

Rug, it doesn't have the normal secondary air doors (counterweight style) or the AVS-style (spring-loaded) "choke plate" above the venturis. It has a bolt-on vacuum diaphragm to open the secondary throttle plates, a la Holley.
Otherwise, it looks like a normal AFB.
I'm only going to be running on the primarys anyway, so it's kind of a moot point how the secondarys are actuated.
It does look small, which is why I am curious about the cfm rating (this is going on a basically stock 170).

Ceej, is there anything else about these carbs to worry about? Why do they have the bad rap?

_________________
O==\=/==O

"A mechanic is Somebody."
- Jim Preston

They are a pain in the patookus to tune.
If your just going to be running in the primary, I'd look into a Holley 390. Put a heavy spring in the secondary to keep it out most of the time. Even with a moderate spring, you won't touch the secondary very often, if ever.
There's a whole lot more info on the Holley, and I've found the Carter/Edelbrock, while easy to tune and unlikely to have leaks, not as easy on fuel out on the road.

Best freeway with 390 vac secondary, 23.9 in '74 4dr valiant with tuna boat bumpers.
Best freeway with 500 AFB, glass bumpers, and 800# lighter, 20 mpg.

CJ

_________________
Part of Tyrde-Browne Racing

I would love to see pics of this type of Carter.

_________________
'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

Weird!

Thank you for the link!

_________________
'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick