Need a source for good quality fitting Zenith Throttle Plates

jquinlan

jquinlan

Senior Member
In the book Restoring Model A and B Carburetors the "Rex" Reheis Way it states the throttle plate should do a good job of sealing the throttle passageway when closed. When shining a light through the carburetor, there should be no light around the edges of the throttle plate (see attached image).

I have a bunch of throttle plates that don't completely seal and looked at the various vendors that sell these but they all look the same to me. Can anyone recommend the best source for good fitting throttle plates. Thanks,
 

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Probably only one manufacturer that all the vendors use. In the back of my mind I'm thinking they only fit one way to be correct.

Paul in CT
 
I can't see much from the pics, but, it appears that the idle speed screw isn't backed off enough.

Back off the speed screw, loosen the throttle plate screws, center the plate and tighten the screws.

I don't think I can remember ever changing a throttle plate on any carburetor. They are not subject to wear.
 
Patrick L. said:
I can't see much from the pics, but, it appears that the idle speed screw isn't backed off enough.
Back off the speed screw, loosen the throttle plate screws, center the plate and tighten the screws.
I don't think I can remember ever changing a throttle plate on any carburetor. They are not subject to wear.
Click to expand...

Patrick, the attached picture is from Rex's book on how it should look and how it shouldn't if it doesn't fit right. A nice snug fit shouldn't let any light through. It's probably not as big a deal as they say in the book. I haven't heard anyone else bring up the fit of the throttle plate.
 
The throttle plate has to be centered with idle speed screw backed all the way so the plate can close, loosen the 2 screws so the plate can move, tap it some to settle it, tighten the screws
The wear to look for is near the throttle shaft, if it leaks too much there the idle speed screw has to be backed out and the idle fuel holes won't get proper airflow by them and it will make it harder to get good slow idle
 
Good Morning...I would speak to Dave Renner at Renner's Corner.734-428-8424 He is a good guy and will have the parts and information you need. Ernie in Arizona
 
Kurt in NJ said:
The throttle plate has to be centered with idle speed screw backed all the way so the plate can close, loosen the 2 screws so the plate can move, tap it some to settle it, tighten the screws
The wear to look for is near the throttle shaft, if it leaks too much there the idle speed screw has to be backed out and the idle fuel holes won't get proper airflow by them and it will make it harder to get good slow idle
Click to expand...

I know what you mean Kurt about centering the plate and finessing it into position.
 
Haven't tried any replacements. Deburred originals work good.
I have several extras if that would help.
I tap them home to get a good tight fit.
 
Brentwood Bob said:
Haven't tried any replacements. Deburred originals work good.
I have several extras if that would help.
I tap them home to get a good tight fit.
Click to expand...
Yep, the originals do fit the best. That's really nice of you to offer up your extras but I have a few that I can make work. Thanks
 
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