johnspd22

Got a question regarding a quadrajet rebuild. I was going to send out a carb I have for a rebuild, but due to lack of funds, have decided to do it myself.

Have some experience adjusting and but I have never rebuilt a quadrajet completely and I was curious on rebushing the throttle plates. Saw some kits with varing costs. Some with bushing, tap and the oh so valuable directions.

Seems, however, that these directions and a tap thrown in add an additional $50 to the aforementioned kit. I have taps already and so I am really just interested in the bushings.

Can anyone fill me in on what this tap is for (I thought the bushings were a press fit) and if the directions are worth a damn.

Thanks!

henryk8398

Rebushing your own Q-Jet is a dicey proposition. The screws that hold the throttle blades to the shafts are very small. I'm not sure which kit you are talking about, that said, what size is the tap?

I'm 1 for 2 on the rebush. I jacked up the most recent one I had to send it out. I sent the throttle body to this gentleman:

http://www.quadrajetcarburetors.com/...tructions.html

He charges about $100 to rebush. If you aren't going to do many of these, it may be worth farming that work out. I wish I had the instructions before I tried it! In fact, I wish I sent it off to him first.

johnspd22

Tap was 3/48. To tell you the truth, I have not checked the carb for play on the shaft yet. not sure if it needs it. Just assumed it was good practice (carb a '73).

Found a good link with some picks, but still was confused on the note about filing down the threads?? Can anyone fill in the blank here.

http://www.thirdgen.org/techboard/po...498-post2.html

Thanks!

johnspd22

Duh! Should have read your link. The answer is right there. Thanks Henryk8398.

Good link. Thanks again.

henryk8398

You're welcome! A 3-48 tap is definitely used for the throttle blade screws. As per the link I sent you, you would have to tap new holes if you break the screws.

I would be very surprised that a 1973 Q-Jet would not need bushing service, unless it's already been done. It's a very common Q-Jet (among other carbs) malady. Check closely, you should be able to see new bushings. It would be obvious since they are either steel or bronze and will be a different color than the aluminum throttle body. If you see bushings, I think you are home free.

Oldsmobomb

Just my 2 cents ... I've rebuilt a fair number of Q-jets from the mid/late 60's and never re-bushed a one. I do understand that severely worn carbs can require rebushing due to excessive shaft play and/or air leaks, but I have never encountered one that didn't idle smoothly and have great throttle response with a standard rebuild.

Maybe I've just been lucky not to run into one that was severely worn, but I've run into more problems with the Carter AFB, than a Q-jet ...

1964f-85

rebushing is critical, if you cant do it, take it to a machine shop and see how much they charge. I machine my own bushings and machine the baseplate on a mill. Anyone you know with a good mill should be able to handle the rebushing proceedure.
I just rebuilt a Q-Jet off of a 68 Toronado and it works fantastic.

johnspd22

Doesn't look too bad. I think I might give it a shot as long as there looks like there is play on the throttle.

Otherwise, I may just rebuild.

johnspd22

1964f-85,

Did you send your pieces out to ge colorized? The one reason I usually send my carbs out is the replating and colorizing. They always come back looking so great.

Just curious. The paint route never looks as good.