Looks like you can add preload to the torsion spring holding it shut by putting another revolution or two on it. It would mean taking the little sheet metal screw out and holding your mouth right while attempting to do it I'm sure.

That wouldn't explain it coming open under some unkown circumstance - but might keep it from remaining open.

 
 Steve Metzger       Tucson, Arizona

I agree, it's a redundant vent along with the original bowl vent. How it's opening I don't know.

       

Gary, 55 Vicky, St. Germain, Wisconsin

 

As far as I can see the gadget is useless - its only on there to duplicate the original Holley build "LIST" number. None of the current crop of 4160 style Holley carbs use them - its simply a potential vapor/fluid leak to be eliminated.

God forbid you have an "uncontrolled" gasoline vapor exit point from your carburetor - the Feds will be knocking on your door at midnight.........   

 
 Steve Metzger       Tucson, Arizona

Ok, and all that arm does is keep it from going closed all the way, you set the gap at the vent at 1/16 inch by bending the vent arm with the throttle closed, the only way I can see it to open is to be blown open.

       

Gary, 55 Vicky, St. Germain, Wisconsin

 

AGhhh its too early in the morning and I haven't had a coffee yet ..I must be blind ,you can see in the picture where the linkage touches the arm .



"Came too close to dying to stop living now!"

Probably didn't explain that well when saying mecanical [meaning its not a vacuum thing] .. Its the spring that closes the arm of the vent, the arm should be resting on some part of the throttle linkage when its closed therefore opening it against the spring pressure. I dont have a 465 with me , Its on the water coming. Maybe someone has a pic of what it touches as part of the linkage.

Any chance of taking a picture of yours so we can help.



"Came too close to dying to stop living now!"

I see no way to mechanically open it, other than your initial setting which is 1/16 inch at the vent. As you accelerate, the throttle linkage doesn't even touch the vent arm, just not sure what would make it go all the way open. The spring is ok and the linkage is correct.

       

Gary, 55 Vicky, St. Germain, Wisconsin

 

Mm? Its mechanical.. The vent should be open when the throttle is closed. As the throttle is opening it should start to close the arm [that is the vent arm]  it is linked to the throttle linkage. In the pic Rick put up you can't see it but it should all work together...The fine spring is not broken is it [see pic], or the arm is not on the wrong side of the linkage?



"Came too close to dying to stop living now!"

Thanx guys, my concern now is, whats making it go wide open, it's designed to be in a closed or almost closed position, no fuel is leaking out, so it must be a pressure differential~ from what? I took it off, WD40 on the clip and its staying at its setting now, but something opened it.

       

Gary, 55 Vicky, St. Germain, Wisconsin

 

You can clearly the vent valve on this hires image from the Holley website.

It should close itself ehen the throttle is closed as it is spring loaded. You can remove it and clean the shaft if need be. I have never known one of the springs to beak unless the car has been out in the weather along time. Mabe a spray of WD40 will free it.



Regards


Rick - West Australia
Do Y Blocks Downunder run upside down? Gravity Sucks!!