750 Holley electric choke question

65 Cuda 340

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Never have run chokes any anything. Back in the day, no problem, let it sit for a month, pump the gas couple of times, fires right up. Then keep foot on throttle to keep it from dying until it warms up a bit (or just drive off; once you get the rpm's up just a little bit, it would run fine).

Those days are gone, as we all know. Today, with any sitting at all, the fuel in the carb and in the line will disappear so if you don't have an electric fuel pump, it's either prime the carb or it's crank, crank, crank, crank etc, etc, until the carb gets enough fuel in it to start the car.

So, noting how easily my 56 Plymouth started after sitting with its electric-choke equipped Edelbrock carb, I got an electric choke kit for the 3310 Holley on my 65 Barracuda. Adjusted so that it is fully closed when dead cold, it now starts after just a few cranks. Problem is, so adjusted, it doesn't open all the way when warmed up. Adjusted so it opens all the way when hot, it doesn't fully close when cold, and partially open it really doesn't help.

Just how open is the choke flap supposed to be when the motor is completely warmed up? Maybe it's not supposed to be fully vertical??
 

GTX JOHN

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No Sir = It will be totally vertical OR you will lose Horsepower!
Keep fooling with it - perhaps play with the linkage to lengthen.
I usually remove the darn things and chick it with my hand after
it has been sitting (Not OSCA approved).
 

65 Cuda 340

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OK, thanks. Will take a more careful look at how it's all set up. Might just need to bend the link to make it longer. Or shorter. Will post whatever I find out.
 

65 Cuda 340

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After looking at the whole setup, it seemed to me that bending the link might move the choke plate one way or the other, but the total travel would be the same. And the problem, it seemed, was a lack of full travel. Looked and looked some more and finally noticed that the choke plate shaft was really loose in its bores. So, looked up choke plate for 3310 Holley, got the pn for it and its shaft. Shaft diameter is supposed to be .317. One that's in there now is no where near that big; more like .222. Have no idea where it came from (OK, been a while since I installed the choke kit and have not been driving any of my old Mopars very much lately). Thinking the plate and shaft had been missing from this carb and that I had robbed what was in there from my parts stash? What did the plate/shaft come from? Dunno, but I have ordered the correct choke plate and shaft. Should be here later this week. Will see if that fixes things.
 
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pishta

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The choke fully closed need not be fully closed. The rebuild manual may give you a 1/32 gap or a drill bit size that will fit between the choke and the horn. Set it at 90 degrees off and let it close where it may. Iirc you can rotate the heater a little to manipulate the "global" rotation clocking. The choke pull off will also pull the choke open a little on full throttle.
 

65 Cuda 340

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If I set the plate at vertical when warm, it's nowhere near closed when cold. To get it to close fully (or almost fully) when cold, you have to rotate the black choke cap to where the mark on it is well past the marks on the housing.

I'm convinced at the moment that the loose shaft is the problem. But of course the proof of the pudding will be in the eating, as the saying originally went.

Let you know if I'm wrong. Should know by the end of the week.
 

65 Cuda 340

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OK, don't know how helpful this will be to anyone since it's possible no one else would be dumb enough to swap the wrong choke plate and shaft into their carbs, but the correct choke shaft and plate seems to have done the job. With it set at closed when cold, it opens all the way when fully warmed up. Will let it cool down now, and possibly make slight adjustment but I think it's really close now.

Here's the comparison of the two choke shafts. Correct one is visibly larger.

20211117_112813.jpg


And new shaft and choke plate in the car, running, after fully warming up.

20211117_122019.jpg


And if you want to hear how it sounds, I just now posted this You Tube video. (The springs on the floor behind the Barracuda are Eaton heavy duty rear springs for my 59 Dodge.) It sounds smoother and quieter in the video than it did when I was standing behind it. I put the cam in probably 20 years ago, when it still had the factory heads and exhaust manifolds. Could use more cam now, but I don't feel like tearing the motor apart to switch.

 

65 Cuda 340

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OK, don't know how helpful this will be to anyone since it's possible no one else would be dumb enough to swap the wrong choke plate and shaft into their carbs, but the correct choke shaft and plate seems to have done the job. With it set at closed when cold, it opens all the way when fully warmed up. Will let it cool down now, and possibly make slight adjustment but I think it's really close now.

Here's the comparison of the two choke shafts. Correct one is visibly larger.

View attachment 1715821631
OK, just found out where the small diameter shaft came from. Am in the process of putting chokes on all the rest of my Holley carburetors because with today's gas it's too durn hard to start my cars if they've been sitting a while. I have two 750 vacuum secondary carbs, one 650 double pumper and two 750 double pumpers. They ALL use the larger shaft except the 750 double pumper on my 59 Dodge. It has the small shaft and a choke plate that screws on (others snap in). Haven't tried to figure out when it was made, but am thinking it's an older version. In any event, fortunately I saved the small shaft and the choke plate for that carb, so it was simple enough to put it back in.

I continually am surprised that things I assume will be the same aren't. (Besides Holley choke shafts, I recently discovered that accelerator pump pistons for Carter AFBs and Edelbrocks are different. Whodathunk?)
 

4spdragtop

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Eddy 1405 & 1406 are the same, shafts are different. Glad ya figgered it out.
OK, just found out where the small diameter shaft came from. Am in the process of putting chokes on all the rest of my Holley carburetors because with today's gas it's too durn hard to start my cars if they've been sitting a while. I have two 750 vacuum secondary carbs, one 650 double pumper and two 750 double pumpers. They ALL use the larger shaft except the 750 double pumper on my 59 Dodge. It has the small shaft and a choke plate that screws on (others snap in). Haven't tried to figure out when it was made, but am thinking it's an older version. In any event, fortunately I saved the small shaft and the choke plate for that carb, so it was simple enough to put it back in.

I continually am surprised that things I assume will be the same aren't. (Besides Holley choke shafts, I recently discovered that accelerator pump pistons for Carter AFBs and Edelbrocks are different. Whodathunk?)
 
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