[JMB36TA]

Originally Posted by Shiny

It's been a while but I remember reading to loosen the threads by tightening, not by trying to back them out. Then continue to tighten and intentionally twist the head off. I think the idea was to then grab the protruding peened stub with needle nose and rotate them ccw to pull them through - no filing.

Is this folklore?

That would work. The one screw I was able to grab easily came out through the bottom.

[Kenth]

Originally Posted by JMB36TA

My throttle shaft problem is solved. I picked up a 71 Pontiac 455 Q-jet 7041262 yesterday for $100. Thanks Paul! I'm going to clean it up and put the new parts from the old carb in it. I'm not going to open up any bypass air channels or idle channels since the old one ran worse after I did that. I'm going to give it a basic rebuild and hope for the best. I can get the correct divorced choke and not have to worry about the modified one coming apart anymore. When I started rebuilding the motor back in June I said I was going to do it right and not cut corners to make things work. Getting a Pontiac Q-jet with the correct choke was on the list.
The last piece for the upgraded distributor will be here today so I can put it back together tonight. I already have it apart and cleaned up waiting to go. The shaft was really gunked up with greasy sticky crud. It spins much more freely now. I should be doing some tuning on Saturday.

Btw...I have Olds Q-jet that needs a new primary throttle shaft for sale...LOL
It ran good before the rebuild and had good response. The old parts will go back in and I'm still going to look for a shaft and get it in working order again.

Looks like a "factory rebuilt Frankencarb".

Carries a non-Pontiac airhorn, phillips head screws, 1970 style choke pull-off, possibly damaged housing inlet threads w/rescue nut, added tube for ported vacuum to ign vac advance.

This would give you hands full of work before it´ll run properly.

[JMB36TA]

Originally Posted by Kenth

Looks like a "factory rebuilt Frankencarb".



Carries a non-Pontiac airhorn, phillips head screws, 1970 style choke pull-off, possibly damaged housing inlet threads w/rescue nut, added tube for ported vacuum to ign vac advance.



This would give you hands full of work before it´ll run properly.

Not sure what the difference is between a Pontiac and non Pontiac air horn or what you’re referring to about housing inlet threads and rescue nut. Can you please be more specific on which threads you’re referring to?

I’m not too worried about Phillips screws or the choke pull off since those can easily be replaced. I’m going to use the new choke pull off I put on my old carb, and maybe I’ll swap out the screws too. The added vacuum will be blocked off since I’m using manifold vacuum for my vacuum advance.


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[Kenth]

A fuel inlet "rescue nut" has larger cutting threads to replace the original nut when the threads in bowl has eroded to the point were they wont hold the original nut.
I may be wrong but the nut on your 71 Qjet sure looks like one.

The airhorn on your carb could be anything but a Pontiac airhorn, so the differences has to be checked closer to know the exact origin.
A 1971 Pontiac Qjet airhorn has a large front bowl vent screw-on assembly, large cut-outs on airvalves and an APT adjustment conical shaped screw under a triangular washer on top for example.

The phillips screws are a sign of crappy internal modifications and mixed brands non-matching parts used.

JMHO

[JMB36TA]

Originally Posted by Kenth

A fuel inlet "rescue nut" has larger cutting threads to replace the original nut when the threads in bowl has eroded to the point were they wont hold the original nut.
I may be wrong but the nut on your 71 Qjet sure looks like one.

The airhorn on your carb could be anything but a Pontiac airhorn, so the differences has to be checked closer to know the exact origin.
A 1971 Pontiac Qjet airhorn has a large front bowl vent screw-on assembly, large cut-outs on airvalves and an APT adjustment conical shaped screw under a triangular washer on top for example.

The phillips screws are a sign of crappy internal modifications and mixed brands non-matching parts used.

JMHO

I'm going to dig into it tonight. I have a new fuel inlet nut so I'll check to see if it fits. Maybe it's for a smaller fuel line fitting???

I'll check for the APT screw inside the maid body when I take the airhorn off. I was under the impression that it wasn't on all models but I don't know that much detail about what models had what features.

[JMB36TA]

Kenth you were right, it was messed with. There was helicoil in the hole for the needle valve that was coming apart. It was unraveling and coming through the fuel inlet passage. One thread in the main body for a base plate screw was stripped and would have to be tapped for a larger screw which really isn't an issue as long as there's no vacuum leaks but the needle valve threads a pretty bad.

[JMB36TA]

So that frankencarb is gone. I swapped it for a service carb off a 428 LeMans, thanks again Paul!! This one is a lot better, it has a nice idle and doesn't want to die. But, there's a loss of power and I can't even get the wheels to spin when I floor it anymore. I was getting wheel ship shifting into second with my old carb. I got in touch with Cliff and I'll have to change a few parts. Got a little more work to do.

[JMB36TA]

Thought I'd post a video of what it sounds like now that I have the carb dialed in.

Thanks for everybody's help!!

[gtofreek]

Sounds good Joe! Now, when do I get a ride?

[JMB36TA]

Originally Posted by gtofreek

Sounds good Joe! Now, when do I get a ride?

Wednesday! I have a carb to return and want your opinion on gears.