frustrated at Carter bbd brand new carb

[JayRamb]

I am so frustrated and at a loss on why my carb is over loading at stay up. If that choke is on a lil bit it over loads when cold. Float has been set to spec. I even lowered a tiny bit. Once that choke opens its fine. This bbd is sucky. The only thing that I can think of is the needle seat. I've had experience with these carbs since 2009. What am I going to do? Everything is in place even the little ball and big ball in the correct places.i can't lean it enough

[AMC of Houston]

I've OH'ed at least 200 BBD's over the years (probably more; but memory fades with age!); a lot of them fresh-from-the-box store-bought rebuilts.   I've yet to see a store-bought rebuilt that was done right.

To start with; be sure the metering rod and accelerator pump height adjustments are dead-nuts on the mark.   Also need to be sure all of the choke adjustments (including the pull-off - be sure it opens up the choke to spec) are also good.   Also drill out the bottom of the air bleed tubes to 0.030 per the AMC service bulletin (rebuilders never do that; and that's a big BBD issue with running rich).   Then adjust everything per the IS-12e service letter (I can send you a scan if you get me your email addy).

Good luck with it.

[JayRamb]

I've OH'ed at least 200 BBD's over the years (probably more; but memory fades with age!); a lot of them fresh-from-the-box store-bought rebuilts.   I've yet to see a store-bought rebuilt that was done right.

To start with; be sure the metering rod and accelerator pump height adjustments are dead-nuts on the mark.   Also need to be sure all of the choke adjustments (including the pull-off - be sure it opens up the choke to spec) are also good.   Also drill out the bottom of the air bleed tubes to 0.030 per the AMC service bulletin (rebuilders never do that; and that's a big BBD issue with running rich).   Then adjust everything per the IS-12e service letter (I can send you a scan if you get me your email addy).

Good luck with it.

NICE! I'll have to drill those out with the 5/16 bit.

[carnuck]

NOT 5/16"!!!!! Maybe 5/32 but I know it's not huge.

Is this a stepper motor carb? Do you have a 3 line filter? (if not, you may have too much fuel pressure like mine did)

I bought the Carter AFB overhaul and metering rod kit with Offroad needle and seat, but didn't get around to seeing if it would fit the BBD too (the AFB 4 bbl is for my 304 or 290 with SP2P intake is buried in my pile of parts and I've been cleaning out all the excess but still have nearly a semi-trailer full to deal with)

[macdude443]

The idle tubes should be drilled to .032".  Should be a #67 bit.

Here is a video that shows the process:
https://www.youtube.com/watch?v=TgQRggcC824