The Ford Barn

SoCalCoupe · 10-30-2021, 06:38 PM

Did the first extended drive today on my stock '41 V8 coupe. Throttle response is awful. Got home and fully analyzed it. It's all mechanical. When I operate the gas pedal, the throttle rod connector fitting pulls all the way open before operating the throttle lever on the carb. Either the spring is weak on the connector or the shaft takes more effort to rotate than it should. Once the throttle lever on the carb starts operating, the accelerator pump linkage starts torquing itself up unnaturally taking all the slack out of the linkage and moves about an eight of an inch before the pump actually moves and gives a squirt.

It drives just like you'd expect with those observations: press the accelerator a little bit and nothing happens while the spring on the accelerator rod connector to carb opens, a little bit more and the throttle plate starts to operate and the car moves slowly, a little bit more and suddenly you get the pump squirt and the car take off like you stabbed the accelerator.

Just rebuilt the carb with a kit so I've done the best job I can do without sending it out to a Holley 94 expert for a professional rebuild.

What should I focus on:
1. accelerator connector fitting to the carb
2. carb throttle shaft
3. accelerator pump linkage.

This car is going to get hot rodded a bit so I don't see myself spending money on a Holley 94 I don't intend to keep. Just trying to get it running correctly in a stock configuration without spending a lot of money before making modifications.

Intentions are either a single single new super 97 or a 97 dual carb setup.

51 MERC-CT · 10-30-2021, 07:53 PM

If the linkage ends are loose and sloppy (springs weak), I would fabricate new linkages using these ends.

https://www.speedwaymotors.com/Carb-...-RH,37495.html

tubman · 10-30-2021, 08:07 PM

Are there any extra return springs on your carburetor? Sometimes when the factory springs get weak (or even break), owners install auxiliary springs, that if mounted at an incorrect angle, can cause the linkage to "cock", causing problems like you are experiencing.

Also, before I wasted any money on a cheap incorrect copy of a Stromberg 97, I would do a little research on what's available out there and look closely at the new Stromberg's made in England that exactly match the originals and are manufactured to the highest standards.

If it were my car, I would seriously consider having my carburetor rebuilt by "Charlie ny". Then you could be sure everything was shipshape. As you may have surmised from some other threads on here, properly adding multiple carbs is more than just a matter of bolting parts together. Get it running well with one carburetor first.

Terry,OH · 10-31-2021, 06:52 AM

Not a lot of experience with 41 but the 40 has small rubber covers over the linkage balls to lessen vibration. The throttle and choke hand linkage at the Carb and all the joints of the accelerator linkage. Make sure they are in place since they often deteriorate and fall off. It sounds as if there is a major problem that should be easy to identify such as linkage that has fallen off.

SoCalCoupe · 10-31-2021, 02:05 PM

Quote:

Originally Posted by 51 MERC-CT

If the linkage ends are loose and sloppy (springs weak), I would fabricate new linkages using these ends.

https://www.speedwaymotors.com/Carb-...-RH,37495.html

That might just do the trick. The linkage ends are loose and sloppy, much more so than for the choke cable and throttle cable.

Quote:

Originally Posted by tubman

Are there any extra return springs on your carburetor? Sometimes when the factory springs get weak (or even break), owners install auxiliary springs, that if mounted at an incorrect angle, can cause the linkage to "cock", causing problems like you are experiencing.

Also, before I wasted any money on a cheap incorrect copy of a Stromberg 97, I would do a little research on what's available out there and look closely at the new Stromberg's made in England that exactly match the originals and are manufactured to the highest standards.

If it were my car, I would seriously consider having my carburetor rebuilt by "Charlie ny". Then you could be sure everything was shipshape. As you may have surmised from some other threads on here, properly adding multiple carbs is more than just a matter of bolting parts together. Get it running well with one carburetor first.

No, there are no extra springs.

Definitely not going to buy a cheap copy of a Stromberg, only the real deal. Thinking seriously about a single Big 97 from Stromberg that flows 250 cfm. Only one carburetor and all the cfm a near-stock flathead would ever need.

Quote:

Originally Posted by Terry,OH

Not a lot of experience with 41 but the 40 has small rubber covers over the linkage balls to lessen vibration. The throttle and choke hand linkage at the Carb and all the joints of the accelerator linkage. Make sure they are in place since they often deteriorate and fall off. It sounds as if there is a major problem that should be easy to identify such as linkage that has fallen off.

Interesting, I don't have those covers, maybe I should.

tubman · 10-31-2021, 02:37 PM

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OK. You seem to be referring to the 250 cfm version of the 97 from England as a "super 97" which is fine. I was afraid you were considering one of the "9Super7" versions from Lincoln, NE and points (much further) east.

Mart · 10-31-2021, 04:14 PM

The return spring should be part of the pedal lever assembly and there should not be any other spring fitted.
Remove the linkage and operate the carb by hand.
Is it stiff or free moving?
Does the accelerator pump operate smoothly or is it stiff and binding?
I did a video recently showing teardown and reassembly of a 94.
There might be something in there that could be helpful.

You need to investigate the problem, as only you can see what is happening.

Try disconnecting the accelerator pump link and watch as the carb butterflies are operated by the linkage. Is the problem still there.

Look at it closely. Study it. Hopefully something will jump out as not being right.

Mart.

SoCalCoupe · 11-06-2021, 08:09 PM

Quote:

Originally Posted by 51 MERC-CT

If the linkage ends are loose and sloppy (springs weak), I would fabricate new linkages using these ends.

https://www.speedwaymotors.com/Carb-...-RH,37495.html

These things are magic. Along with a 3/16" zinc plated rod from Home Depot, they made a 95% improvement in my throttle response. I have real fine control over the engine with a solid accelerator linkage. Drives like a real car now, not an old POS. The throttle rod might have been original and the springs (just like the ones in this picture) might have simply lost their tension after 80 years.

tubman · 11-06-2021, 09:44 PM

Congratulations on getting it working so well. It's amazing that sometimes it's just the simple things.

52flthed · 11-07-2021, 12:55 AM

This is exactly what happened when I had my original carburetor rebuilt. Brought it back, shaft was replaced and extra springs on the plunger but it was still un- drive-able. Finally had to replace it with a brand new reproduction, now it runs flawlessly. So despite changing my other throttle linkage I now know it was the carburetor. I miss the original one and still want to get another shot at getting another one rebuilt.

10-30-2021, 06:38 PM	#1
SoCalCoupe Senior Member Join Date: Sep 2021 Location: Point Loma, San Diego, CA Posts: 424	Thoughts on what to do with a bad carb linkage? Did the first extended drive today on my stock '41 V8 coupe. Throttle response is awful. Got home and fully analyzed it. It's all mechanical. When I operate the gas pedal, the throttle rod connector fitting pulls all the way open before operating the throttle lever on the carb. Either the spring is weak on the connector or the shaft takes more effort to rotate than it should. Once the throttle lever on the carb starts operating, the accelerator pump linkage starts torquing itself up unnaturally taking all the slack out of the linkage and moves about an eight of an inch before the pump actually moves and gives a squirt. It drives just like you'd expect with those observations: press the accelerator a little bit and nothing happens while the spring on the accelerator rod connector to carb opens, a little bit more and the throttle plate starts to operate and the car moves slowly, a little bit more and suddenly you get the pump squirt and the car take off like you stabbed the accelerator. Just rebuilt the carb with a kit so I've done the best job I can do without sending it out to a Holley 94 expert for a professional rebuild. What should I focus on: 1. accelerator connector fitting to the carb 2. carb throttle shaft 3. accelerator pump linkage. This car is going to get hot rodded a bit so I don't see myself spending money on a Holley 94 I don't intend to keep. Just trying to get it running correctly in a stock configuration without spending a lot of money before making modifications. Intentions are either a single single new super 97 or a 97 dual carb setup.

10-30-2021, 08:07 PM	#3
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,319	Re: Thoughts on what to do with a bad carb linkage? Are there any extra return springs on your carburetor? Sometimes when the factory springs get weak (or even break), owners install auxiliary springs, that if mounted at an incorrect angle, can cause the linkage to "cock", causing problems like you are experiencing. Also, before I wasted any money on a cheap incorrect copy of a Stromberg 97, I would do a little research on what's available out there and look closely at the new Stromberg's made in England that exactly match the originals and are manufactured to the highest standards. If it were my car, I would seriously consider having my carburetor rebuilt by "Charlie ny". Then you could be sure everything was shipshape. As you may have surmised from some other threads on here, properly adding multiple carbs is more than just a matter of bolting parts together. Get it running well with one carburetor first.

10-31-2021, 02:37 PM	#6
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,319	Re: Thoughts on what to do with a bad carb linkage? Sponsored Links (Register now to hide all advertisements) OK. You seem to be referring to the 250 cfm version of the 97 from England as a "super 97" which is fine. I was afraid you were considering one of the "9Super7" versions from Lincoln, NE and points (much further) east.

10-31-2021, 04:14 PM	#7
Mart Senior Member Join Date: May 2010 Location: Solihull, England. Posts: 8,755	Re: Thoughts on what to do with a bad carb linkage? The return spring should be part of the pedal lever assembly and there should not be any other spring fitted. Remove the linkage and operate the carb by hand. Is it stiff or free moving? Does the accelerator pump operate smoothly or is it stiff and binding? I did a video recently showing teardown and reassembly of a 94. There might be something in there that could be helpful. You need to investigate the problem, as only you can see what is happening. Try disconnecting the accelerator pump link and watch as the carb butterflies are operated by the linkage. Is the problem still there. Look at it closely. Study it. Hopefully something will jump out as not being right. Mart.

11-06-2021, 09:44 PM	#9
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,319	Re: Thoughts on what to do with a bad carb linkage? Congratulations on getting it working so well. It's amazing that sometimes it's just the simple things.

11-07-2021, 12:55 AM	#10
52flthed Senior Member Join Date: Oct 2019 Posts: 175	Re: Thoughts on what to do with a bad carb linkage? This is exactly what happened when I had my original carburetor rebuilt. Brought it back, shaft was replaced and extra springs on the plunger but it was still un- drive-able. Finally had to replace it with a brand new reproduction, now it runs flawlessly. So despite changing my other throttle linkage I now know it was the carburetor. I miss the original one and still want to get another shot at getting another one rebuilt.