Hi all,

I'm trying to set the accelerator pump travel on my Carter BBD (2-bbl, from 77-80 Aspen/Volare) but I'm confused by the terminology being used in the instructions that came with the re-build kit. Below is the screw that adjusts the pump travel:



The instructions (in Fig. C, below) say to "measure from the top of accelerator pump shaft to top of bowl cover". It's not clear to me what distance they're measuring. The bowl is underneath this whole assembly, so is the "top of bowl cover" the flat surface below the shaft? Or do they mean the top edge that's above the shaft (where the dust cover is screwed on)??? And the shaft itself doesn't move up or down, so are they measuring from the pump arm, or from the top of the plunger?

So, what are the results if this isn't adjusted properly? I'm assuming I could either waste fuel, or maybe not pump enough fuel? As always, any help is much appreciated, thanks!!

Roger

A bump for you...since the only BBD's I have played with are the older style with the external accelerator linkage.

As for it being out of adjustment...can lead to a stumble off idle or just general throttle transition..

There is no bowl cover, the instructions should say dust cover.
Your BBD should have the pump shaft's tip adjusted to 1/2" below the level of the dust cover surface after the idle speed screw has been set to 2 turns in. There should be a 1/2" gauge to set it with in your rebuild kit.
Also make sure the step up piston adjustment is correct.
The BBD (from a 318) on my 225 '84 D100 was running badly from being too lean as a result of the new 10% ethanol gas. I turned the screw in shown in step one to fatten it up till I can jet it up one size, it lifted to rods up just enough to get me by for now. The Super Six BBD on my 225 '79 Aspen seems to be uneffected from the 10% gas.

Thanks for the bump, Oz.

And thanks for the explanation, B5. That makes more sense. I did get a gauge with the kit, so I'll measure it tomorrow.

As for the step-up piston adjustment, how far did you turn yours in? My car is running a bit rich, so I backed that screw out about one-half turn. But I'm not sure how much effect (if any) such a small adjustment will have. I'll probably just play with it until I get it right.

That looks like a 318 model BBD. Should have same jets as a super six. Just the rods are richer (smaller in diameter)