Zenith Throttle Valve Inspection

[dennisv]

I have a pair of Zenith 40 TIN that I've started to rebuild. My first venture into carbs. I read the following in a Weber manual that I'm using to augment my understanding:

Hold carburetor up to a light and close throttle. No light should be visible around any of the throttle valves.

I assume this is a general inspection procedure and would apply to Solex and Zenith carbs as well?

In looking at mine, I have one that seems pretty tight. Another has quite large gaps. What is this a symptom of? What are the potential fixes for this?

Thanks.

[Nditiz1]

You can loosen the collars at the bottom to allow the butterfly to reset. They should all open the same so no light all closed, minor light even on all with minor opening of the throttle.

[targa72e]

The butterflies all have to be aligned so they open the same. As mentioned above you can loosen the couplers to adjust. You can also look thru the transition holes after removing plug and make sure all the butterflies are aligned to the same spot.

john

[1QuickS]

Check for broken throttle shaft coupler, Zeniths tend to suffer this problem.