#3367 carb primary throttle plates

[Rob A.]

I noticed with the throttle fully open and the lever against the mechanical stop, the primary throttle plates are not fully open. They are about 1/4" short of being 90 degrees to the bore. Am I correct that they should be full open when the lever on the shaft reaches the mechanical stop?

[Clem Z.]

Re: #3367 carb primary throttle plates

yes they should be open a full 90 degrees. i would guess the throttle arm on the side is loose on the shaft or it was loose and was refastened in the wrong place. i have see this before

[Rob A.]

Re: #3367 carb primary throttle plates

Clem,

It looks the inner lever, that contacts the carb base to mechanically stop the throttle plates from opening further, is one piece with the shaft. I see where the outer lever could have been re-fastened in the incorrect position, but not the inner one. It looks like I would have to bend the inner lever to allow further opening of the plates. Is there any possibility this particular carb (original #3367) was meant to be set up this way?

[Clem Z.]

the inner lever is brazed to the throttle shaft

so it must have gotten bent or was brazed on incorrectly.i would not think this was build or designed this way.

[Rob A.]

Re: the inner lever is brazed to the throttle shaf

Clem,

It sure doesn't appear that the inner lever was re-brazed. I would think there would be an index of some type to only allow the lever to be positioned correctly. It looks too neat, and there aren't any signs of repair. I agree that it would make sense that the primary plates should open fully, but they do allow the secondary plates to open fully as it is. Any other thoughts???

[Rob A.]

Hey Clem...do think at some time the primary

throttle shaft could have been replaced, and the wrong one used? It appears original, with the lever peened in place. I noticed the primary shaft is shiny metal and the secondary appears brass. Both have the plates attached correctly with the screws staked.

[Clem Z.]

could be just a screwup when the item was made

and never QCed. since holley does not sell shafts seperatly it could have be changed out with a shaft from different carb causing this problem

[Gerard F.]

Both shafts are steel

Rob,

On my original 3810, the primary shaft was white zinc or cad plated and the secondary shaft was zinc or cad dichromate (looks like brass). The inboard lever on the original primary looks like it was pressure fit and is not loose like the replacement I have. Also the replacement has a bare primary steel shaft and a black (phoshphate?)secondary shaft.

If your inner lever is tight to the shaft (just saw your other post), maybe you ought to think about bending the lever or grinding the stop area. Replacing the shaft is an off the car job, and you might have a task getting those plastic tape bearings back on, in the right place.

It you have to go that far (replace the shaft, that is) you might as well go for a new throttle plate assembly.

Jerry Fuccillo
#42179