I am rebuilding my Carter YFA feedback-type carburetor. I have everything torn down and cleaned and a rebuild kit coming from Napa.

Please excuse my ignorance, with that, my questions.

There was a device between the carb and manifold. Actually, here's a pic:



The person before me did a "smog delete" of questionable quality. My question is, do these two pipes that were cut and bent need to be properly plugged? I am asking because I cannot budge the bolts with even the largest wrench. Right now they are soaking in PB Blaster; ready for the vise and leverage pipe if need be. The one short stubby pipe was bent but is rusted through, the other I can't tell if it is plugged or not but I tend to doubt it. I am wondering if these should be plugged for vacuum purposes.

I guess I would also be entertained by some education if someone felt so inclined to tell me what the name of that part is and what role it plays in the fuel/exhuast system.

Thanks in advance. Just for giggles, here's the disassembled carb:

 

That's the EGR valve and its adapter/mounting plate. Obviously it is not being used, so if it is not leaking at the bent/crimped pipes, just leave it alone and reinstall as is.

 

The part you are playing with is the exhaust gas recirculation valve - the EGR valve, and is part 9A589 in the illustration below. Part 9D477 is "Tube (exhaust gas recirculation valve to exhaust manifold" according to the master parts catalog. I'm not sure what the other pipe is as the drawing doesn't show one. But w/o the EGR valve functioning you can just bend the pipe over to seal it. Or, you can plug the whole if you can get it out.

However, w/o EGR your carb's jetting isn't going to be quite right. It'll run, but probably not the way it should. EGR doesn't really hurt anything.

 

OK, the small bent pipe is rusted through; you can't see it from the angle I took the shot, but there is a hole. I can't get the bolts off. I have a 4' long or so pipe for leverage and the bolts are just rounding. The only way i am going to plug those holes is to drill and tap... equipment I don't have readily available (if at all). So my question now is... if the hole is unplugged, is that going to substantially impact running condition. If so, can the carb be mounted directly to the manifold? If either option is a no-go, maybe I should look around for part 9A598?

 

If the pipe you are talking about is the one from the exhaust manifold, then it can be left open if the EGR valve is both closed and not being used. You have to make sure the valve isn't leaking as you don't want air to be coming into the intake there.

On the other hand, if you aren't using the EGR valve then you can leave it off and bolt the carb directly to the manifold. If the studs are too long you may be able to pull them and replace them. Or, put spacers on top of the carb, although that'll look ..... odd.

 

If you look at my original photo, there are two holes (left and right) of the main opening. Below the main opening is a third hole; it leads to a threaded nut with a very short nub of bent pipe; that's the one rusted through and leaking... I suspect bringing dirty air into the intake. I am looking for a replacement but having a hard time.

Is there some kind of spacer that would plug that third hole altogether (in place of the EGR assembly), or am I imagining something that doesn't exist for a reason? I couldn't directly bolt the carb to the manifold because of that third hole.

 

you would have to weld the hole.
And then there is the throttle linkage problem with the carb sitting an inch lower.
Most people remove the pipes and use brass plumbing plugs on the EGR spacer.

I don't know of any aftermarket spacers that are made to cover the hole in the manifold.

 

Good catch. The best approach is, obviously, to use the spacer and plug the holes.

 

But the OP obviously doesn't have a sharp pipe wrench and a vise...

 

Nope. Heat? Probably not as it has been quite hot in service. Braze it?

 

Not sure, but I doubt he has an O/A setup either...
With a torch you could easily get it hot enough to unscrew.

Wonder how much one used is on Ebay?
I know an EGR blank off is under $5

 

Looks like the part # is:
80/86 E-F-U150/350 - - wl 6 4.9 E4TZ 9A589-H
unleaded fuel *CM-2417-E

 

'70's 250-350 had no EGR from the factory.
I bet a spacer piece is still there though.

I don't know which MPC you are pulling these numbers from though.
Mine is only '80 on

 

Mine is the same as yours. PM coming.

 

Gary, thank you for the part numbers, that was super helpful. I found one on eBay and ordered it. When it comes I'll plug the two holes and mount it in place of what I have now. Thanks for your help on this.

ArdWrknTrk: I found the part on eBay for just under $15 with shipping.