I know there are quite a few here...

I have a Rochester 4 barrel. Take a look at the photo, the way the accelerator pump lever is attached. I am familiar with the two tabs and roll pin holding it in. But in this case the one tab and a brass screw. The screw becomes loose at times. How was this orginally attached on the one tab tops? I want to get back to that way or keep the screw from getting loose.

 

I'm inside where it's warm, but I think I have a roll pin where your screw is located with a cotter key into the roll pin on the back side. But, you know, there were many, many of these manufactured. Might help to display the Model No. you have in the image. I can barely see it in the image.

 

Well, maybe I don't even have a cotter key in the back of the roll pin. It is clearly a roll pin though, unless you can find documentation to prove otherwise, Hey, anything is possible.

 

Interesting. To my knowledge no quadrajet was ever made like that. They had to tabs and the roll pin. What has happened is somebody broke the outer tab off and simply threaded the other tab and put a screw in it. Take the screw out and put some Locktite on the threads and it will stay. You ask how I know this. I recently did the exact same thing on the quadrajet that is on my 75 Hurst/Olds.

 

Someone may have bored out the original hole for the roll pin to accommodate that screw? Possible. In which case you'd need a new pump actuator and roll pin.

 

Here's a full-on diagram if that helps you any....

 

Thanks, Glenn,

At first glance I thought the same and the tab was broken off. But there is no indicator of ever a second tab on there. Fall back is lock tite.

 

answering my own question:

Quadrajet Accelerator Pump Arm Casting Repair (quadrajetparts.com)

For the life of me, I still cannot see the remains of the broken outer tab...…….

 

Everyone I ever worked on had the roll pin, my guess is it was modified at some point.

 

I have Cliff Ruggles book on quadrajets. It has a picture of a very early quadrajet from 1966 and it has the roll pin. Put some Locktite on it and forget about it.

 

I'm not clear Rochester ever made a single (one) tab post for the accelerator pump actuator. Yet, you failed to answer my question when I asked you for a Model No. Evidently the Model No. is unimportant I can only assume. You stated:

What makes you think Rochester built a one tab post for the actuator? Again, maybe if you provided the Model No. of the carburetor we could put this to rest and determine if that Model No. carburetor had a supposed on tab metal post. This should not be such a seriously difficult question to answer.

I have never seen a one post metal tab on any Rochester - the metal tab post (IMO) has broken off, someone most likely smoothed off the base of the broken metal tab post. I can see where the screw is a make-shift operation at best.

 

So, the make-shift screw you see in your airhorn metal tab (pictured) is supposed to replicate/approximate this casting repair. But, you have a screw in its place & this screw works its way loose at times. So, yes you answered your own question - there were no one tab metal posts made by Rochester - yours is broken off and you'll never get back to the way it was installed because there never was a one tab metal post. You either buy an airhorn with the correct two metal tab posts or you live with a make-shift non-OEM operation. The one in the kit doesn't look bad, if it has some longevity to it.

 

Norm, I already knew from a few years ago, that when the carb was rebuilt the air horn assembly was swapped out from another carb (If I recall there was a slight warping on the original). The model number was in the picture, but has less relevance since the carb now has a bit of a mix of parts. I could not see any remains of a broken tab, so I thought there possibly were single tabs that were made, especially considering the number of years these carbs were used and I am definitely not familiar with every version of these things, hence the reason for the post.

 

Same here. I broke the outer tab off back in the 1980s and repaired it. Mine was a bit differfent as I used a small machine screw, threaded it into the remaining tab, then tightened a nut on the backside to hold it in place. As already said, a drop of loctite on the threads of that screw will achieve the same result. Note that my repair was done 40 years ago and no issues in all that time.

 

Pat - I was not 100% certain either - the reason I asked for the Model No. - you never know. I never saw a repair kit offered either, though. Guess it happens with some frequency. They most likely used a Dremmel metal polishing blade to smooth it down. I did go out into the man-cave thinking the off chance I'd maybe find one (I have three on the bench, one is a Chevy) - they all had two posts.

 

Thanks Norm for looking. Either my eyesight is getting worse or they did a real great job grinding it down and blending it in. It was a few years ago, so that memory not as good either!

 

The horse should be in the barn by now and you all are still trying to ride the poor bastard. Kenneth I originally had a nut on the backside to use as a locknut but then the air cleaner wouldn't seat down like it is supposed to. That was when I went to the Locktite. I did like you and threaded the remaining post for a machine screw which I believe was a #6. I had to drill the lever out ever so slightly.

 

I see 7041250.

 

I filed a small notch in the lip of the air cleaner so it sat flush on the air horn. It also helped with clocking the air cleaner correctly.

 

You guys are more ingenious than me on that fix. I would have swapped out another air horn. That’s not to say I haven’t Jerry-rigged a few throttle cables to get ‘em to work.

 

My biggest takeaway from the post, is that this sounds like a pretty common problem. Does that tab fail when the lever pin is being driven out during a rebuild?

 

Pat - That's a great question. I've rebuilt maybe a dozen Quadrajet carbs & I've never worried about punching the roll pin into the hole(s) to secure the actuator - I always use a punch/drift rather than the entire hammer head; yet, I think what you suggest is the most likely culprit. Obviously, it's common enough to warrant a repair kit it's the first time I've actually seen a repair kit for this.

 

I re-read your post - you were asking about driving the roll pin "out" rather than "in". Hmmmm......I've never driven the roll pin "out" with any type force. All I've ever needed was to slightly tap the roll pin far enough out to get a piece of the metal roll pin into the blades of a set of dykes (some refer to as wire cutters). Then I simple roll/rotate the dykes and the roll pin comes out easily.

 

jet and a couple other rebuilders use a shouldered screw for repair . ive done a couple using a brass screw drill the arm out to size. actually a fine repair

 

This repair kit works nice. Very easy to use. All you have to do is drill the hole a little bigger on the lever and add a drop of red loctite and tap it in.

 

if you look closely, you can see the distorted cast where the other tab used to be. the shape is still left in the cast where it broke off. hope you get it fixed.

 

See the yellow circle, that area broke off