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How Hard Should I Hit this Thing Anyway?!!!

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GA72TR6

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In a recent post, I described a problem I had with my '78 running rich...smoking, sputtering, blackening my plugs, and petro-stink at the tailpipe. I dismantled/rebuilt the carb including the diaphram and verified that the heat mass in the H20 choke was heating up and working properly. Checked out A-OK. I tuned the idle and enrichment and.....still smoking, etc...

This evening I finally took a deep dive into the choke iteself, removing it from the carb, dismantling and cleaning everything. I think I found the culprit.

The last piece I checked was the enrichment pin which, as near as I can tell, should move up and down freely to let additional fuel flow/not flow into the carb. The mechanism seems to work like the valves in a trumpet. But to change notes on this horn, you have to smack the valve with a hammer and pull it back out with pliers!!!

The pin was stuck quite securely in the up (choke on) position and I can't imagine that the tiny rotating parts in the choke have enough gumption to move it. Ah, ha!

Based on an article I was reading, I removed the breather valve from the opposite side of the choke body, inserted a thin hex wrench through the hole down to the needle, and tapped on the top of the enrichment needle. With several light whacks, it did move to the down (choke off) possition. However, only with some force with needle-nose pliers does it return to the choke-on possition. I can't imagine this is how it's supposed to work, so I assume I've found my problem.

The article explains that you can "tap" the needle down and continue tapping until the whole valve assembly comes out. I attempted this procedure so I could clean/lube it so it works properly (i.e., smooth up/down, choke-on/off with movement that is light enough for the small parts in the choke to actuate...I assume). But this guy is stuck!

I can certainly put muscle into it and drive it out, but don't want to damage anything. How much force should I be using here to remove the enrichment valve assembly to remove and/or unstick it....or am I barking up the wrong tree (again!)?

Please help me get back on the road this weekend...the weather should be too nice here to pass up!!!!
 
I'm inclined to say get some spray-can carb cleaner and some PB Blaster. Start soaking the thing with the Blaster, tap *lightly* to get it as far back-and-forth as possible. The Blaster should allow you to loosen it to a point you can remove it, then REALLY clean it with a "gunbarrel" brush and the carb cleaner.

HTH, good luck!
 
That must be one really stuck choke needle. Mine moved very freely on its own when I had it out. I agree with Dr., lots of Blaster or penetrating oil and tap gently.
 
Mine was stuck pretty good, too. And that stuck plunger will definitely cause rich running. Be patient and keep at it.

Also, you won't be sorry you rebuilt your carb.
 
Most of the moving parts in that auto choke are machine fit and should move easily. If you want to know that the choke is the culprit then duct-tape over the mounting holes and run it a while. You must set the clearances exactly as the factory manual advises especially if someone has disturbed the setscrew with the locknut. That is not the idle screw.

Alan T
 
Bingo...that stuck needle was the source of all my problems. Removed, cleaned, oiled and reinstalled...and she runs like a top!

In addition to being stuck inside the inrichment tube, it was also turned so that the notch on the needle did not line up with the little tang on the back of the rotating arm that moves the needle up and down. So, it was both stuck AND disoriented.

I soaked the choke body in carb cleaner over night. That freed up the needle's up and down movement. (I ended up just removing the needle...not tapping out the entire enrichment tube.)

Next, I removed the C-clip from all the rotating parts and CAREFULLY removed and bundled them together with an unwound paper clip (I understand it can be a bear to get those little parts back together after the spring uncoils and unhooks, so beware!).

I turned the now free-moving needle so the notch was oriented to face backwards out of the opening in the choke body (not sidways, like the PO must have done), then reinstalled the rotating parts bundle so the top tang aliged in the groove on the vacume arm and the lower aligned with the groove on the enrichment needle. Put that C-clip back on, reinstalled the choke, adjusted the idle and BANG....she's a new car.

Pardon my excitement, but this is my first adventure with carburation and after completely rebuilding an entire Stromberge and the "dreaded" water choke, everything appears to run like new. I'm ready for my next carb now....bring it on!

Thanks for everybody's help!!!!!
 
Outstanding, now you can say you did it yourself.
 
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