carter bbd carb

[priceg]

I am thinking about going into the bbd mail order carb overhaul and exchange business. Any takers?

 

[hagar]

First... that is DEFINITELY NOT a Carter BBD. No way nohow. It's... I think... a Carter YF, which would be about right for an '83.

umm, it is a Carter BBD carb.
appears to be the type without the stepper motor.
it's also missing the sol vac and bracket assy; it would mount on the drivers side of the carb, where all the idle adjustemnts are.
which controls the idle speed, electrically, or by engine vacuum.
#22 in the pic

 

[Trapshooter]

If that isn't a Carter BBD, I don't know what is.

Just put a kit into mine on the '86 this last weekend. Took my time and once I was able to get the idle mixture set correctly my AMC 258 i6 / 4.2l has never run better.

 

[Jeepmerunning]

It is a Carter. Their name is on the side. I thought it was a 2bbl, but an earlier post said maybe it's a Carter YF. Back when my rebuild project started a Jeep shop mechanic suggested to go with a replacement carb for an earlier model than my 1985, which might suggest YF. The choke plate does not close over the carb even when cold. I can close it some with my hand, and the idle is fine. But the idle cam will not adjust on its own. I figue it's that ajustable round piece with the red wire attaching to it (image number 3 on page 1.) I was considering a manual choke conversion or ditching the Carter for another brand.

 

[TDHofstetter]

See above...

That it is - or more accurately, it's your "electrically assisted choke". The choke itself is entirely mechanical, but the pulloff (for when the motor's warm" is electrically assisted. Here's the deal:

Inside that black cap is a spring-looking bimetal element just like the one in all the older-style house thermostats. When it's cold, it winds up tightly and when it's warm it loosens. When it winds up (cold), it closes the choke plate at the top of the carburetor, inside the air cleaner (take the air cleaner off to see it) so's to enrich the fuel mixture - the motor needs a richer mixture to keep running when it's cold.

When it warms up (that red wire connects to a tiny heating element inside the black cap, and that little heating element runs any time the key is turned on), the motor doesn't want that rich a mixture (it'll flood), so the springy dude loosens and that opens the choke plate at the top of the carburetor to lean out the fuel mix.

You can only reasonably adjust that choke cap by taking the air cleaner off. With the engine dead cold (sat overnight), the choke plate should close fully and kinda' snugly but not really tightly. It should close with enough force to hold a pencil in place, but not a whole lot more than that - it shouldn't, for example, hold a screwdriver in place. You adjust that force by loosening those three screws and rotating the black cap.

Then when the motor's warmed up, the choke plate should be fully open... which should happen entirely automatically.

With the choke plate closed, your idle speed should follow the fast-idle cam. With the choke plate open, when you tap on the gas pedal the fast-idle cam should drop free and the idle speed should then be controlled by the low-idle screw.

Let's get that choke pulloff (the black cap) adjusted correctly & take it from there. That's probably part & parcel of the problem at this point. It's possible it's been hurt (rust or the heating element burnt out), but it's a LOT more likely that it only needs adjustment.

Loosen the three screws holding that black cap in place and twist it to adjust the choke. Then adjust your idle mixture with the engine warmed up.

 

[cjdizzle]

maybe you guys can help me. ive got a carter on my 81 CJ7 with the AMC 258 i6 / 4.2l . there are 2 hoses that "T" into 1 hose. (circled in pic) the hose was cut and didnt run to anything. (thanks PO) can i plug these or do they need to go to something. the carb in the pic is just usd as an example, not mine. the emissions stuff (egr) is ripped out of mine

 

[TDHofstetter]

Those are bowl vents. You CAN cap 'em, but it'd be better to leave 'em open to the atmosphere with a little filter on each one - one very simple way to accomplish that is to pick up some airstones from your local aquarium supply place; you can adapt down to the size of hose (about 1/8") that fits the airstones because there's nearly zero airflow in either of those lines. The airstone acts as a pretty decent filter, keeping dirt & out of your carburetor bowl while still letting the bowl breathe (helps prevent vaporlock).

 

[cjdizzle]

finally got this thing remounted. do i need to fill the bowl before i start this thing or what?

 

[TDHofstetter]

Wouldn't hurt, it'd save you some cranking. If you've got an electric fuel pump, it won't matter much - just wait till the pump stops rattling; the bowl will be full then.