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Old 10-31-2020, 05:09 PM   #1
54blackhornet
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71 350 Divorce Choke Adjust ? QJet

I just can’t seem to get it to close completely. Engine will not start when cold unless I get out and push throttle linkage back and manually push down on the air valve. It then starts up perfectly. Any tips on getting air valve to close completely by pressing accelerator pedal would be great..Jack
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Old 10-31-2020, 05:51 PM   #2
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Re: 71 350 Divorce Choke Adjust ? QJet

You might need to make your linkage rod from the coil to the carb slightly shorter.
Bending it sometimes works.
Making a new one will work too.
Old clothes hangers work nicely if you need a piece of wire.

What do you have for a base gasket between carb and intake?
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Old 10-31-2020, 10:18 PM   #3
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Re: 71 350 Divorce Choke Adjust ? QJet

Not to be rude or unkind but are you following the starting procedure?

If so can you post a photo of the passenger side of the carburetor? There are literally dozens and dozens of different choke stoves that were used on GM cars over the years you may not have the correct one.
They can go weak and not have enough travel to operate the choke correctly under all conditions.

Here is a link to what I did on mine. Scroll to post 618? Now mine has an electric choke and not the choke stove. Where I rotated the electric component you will bend the linkage to get the same effect. If I remember correctly making the linkage shorter will close the choke more.

https://67-72chevytrucks.com/vboard/...698377&page=25

Keep us in the loop. And good luck.
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The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377
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Old 11-01-2020, 01:35 PM   #4
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Re: 71 350 Divorce Choke Adjust ? QJet

I think I know how to properly start the truck ? When it’s cold it will never start with just one press of the throttle. If it’s warm it will every time. If I open the air cleaner and push down on the air valve completely while pushing the throttle linkage back, the engine starts right up. I quest I will have to continue playing with the linkage to the heat stove... Jack
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Old 11-01-2020, 02:26 PM   #5
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Re: 71 350 Divorce Choke Adjust ? QJet

Quote:
Originally Posted by 54blackhornet View Post
I think I know how to properly start the truck ? When it’s cold it will never start with just one press of the throttle. If it’s warm it will every time. If I open the air cleaner and push down on the air valve completely while pushing the throttle linkage back, the engine starts right up. I quest I will have to continue playing with the linkage to the heat stove... Jack
Interesting -- some of these old beasts seem to have their own personality, and their own unique starting procedure. Starting mine from cold, press the gas pedal once, just enough to set the choke..... do not touch it again or the engine will flood, guaranteed. If the engine is warm, crank it over without touching the gas pedal at all..... or the engine will flood. It's been like that for as long as I can remember, through carb rebuilds, an engine rebuild, and choke replacements.
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Old 11-01-2020, 02:45 PM   #6
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Re: 71 350 Divorce Choke Adjust ? QJet

Quote:
Originally Posted by 54blackhornet View Post
I think I know how to properly start the truck ? When it’s cold it will never start with just one press of the throttle. If it’s warm it will every time. If I open the air cleaner and push down on the air valve completely while pushing the throttle linkage back, the engine starts right up. I quest I will have to continue playing with the linkage to the heat stove... Jack
Check out a new choke spring, maybe just at the parts counter, comparing it with the springiness of your old one? The cold height could even be different.
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Old 11-02-2020, 01:49 PM   #7
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Re: 71 350 Divorce Choke Adjust ? QJet

Quote:
Originally Posted by 54blackhornet View Post
I think I know how to properly start the truck ? When it’s cold it will never start with just one press of the throttle. If it’s warm it will every time. If I open the air cleaner and push down on the air valve completely while pushing the throttle linkage back, the engine starts right up. I quest I will have to continue playing with the linkage to the heat stove... Jack
I did not mean to offend you sir, but you would be surprised the number of times I have asked that question and found out the owner was trying to start the engine like they started a new fuel injected engine.

One thing you should check is how easy does the linkage the choke stove is operating move. The stove should be closing the choke plate completely once the primary throttle plates are completely open. The stove has no power to overcome any resistance in the linkages.
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The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377
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Old 11-03-2020, 11:43 AM   #8
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Re: 71 350 Divorce Choke Adjust ? QJet

No offense taken at all ! I have the fiber type gasket between the manifold and carb. One pump of the gas pedal does not completely close the air valve. If I manually close it the engine fires right up. Guess I will try to shorten the linkage rod again.
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Old 11-03-2020, 12:17 PM   #9
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Re: 71 350 Divorce Choke Adjust ? QJet

If a shorter rod doesn’t help then look at the choke pull off linkage rod. It might be keeping the plate from closing.
Not absolutely certain on that idea but have a look at it.
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Old 11-03-2020, 04:38 PM   #10
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Re: 71 350 Divorce Choke Adjust ? QJet

Today is probably the last warm day for a while so I’m going out to try to adjust the heat stove linkage now. I will update my progress. ..
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Old 11-04-2020, 11:47 AM   #11
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Re: 71 350 Divorce Choke Adjust ? QJet

I tried to adjust the heat stove linkage but noticed that the stepped idle piece is keeping the air valve from closing completely. Suggestions would be great...Jack
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Old 11-04-2020, 02:52 PM   #12
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Re: 71 350 Divorce Choke Adjust ? QJet

Pics of your carb choke side would help.
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Old 11-04-2020, 03:55 PM   #13
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Re: 71 350 Divorce Choke Adjust ? QJet

Thanks I will try to get a few loaded today.
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Old 11-08-2020, 09:42 PM   #14
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Re: 71 350 Divorce Choke Adjust ? QJet

Quote:
Originally Posted by 54blackhornet View Post
I tried to adjust the heat stove linkage but noticed that the stepped idle piece is keeping the air valve from closing completely. Suggestions would be great...Jack
You'll need to hold the throttle about 1/4 of the way open so the fast idle screw doesn't interfere with the movement of the fast idle cam while adjusting the choke. There is also a 'choke unloader' mechanism that forces the choke open when the throttle is wide open. I think it acts thru the fast idle cam.
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