Zenith carb

[Nick in Fayetteville]

Does anyone make a better drain plug gasket than the ones found in the Zenith rebuild kits. Even with sealers, those still leak. Thanks

 

[larrys40]

Are you sure It’s the drain plug?
Put a finger in the carb throat and see if it’s wet on the bottom . If it is wet , it is not your drain plug. It is your float valve or float level.
Larry shepard

 

[Gary WA]

Drain plug is not there to stop leaking carb! Check your float or jets for proper tightness, and setting height. also your shut off valve!

 

[johnbuckley]

I agree with #2 ... the drain plug often get blamed ( and subsequently often overtightened and threads stripped in consequence!). It is likely the leak is elsewhere and fuel just trickling down to the lowest point. However I always use a very small smear of sealant ( I find Blue Hylomar the best over here ) on all the gaskets.

 

[Nick in Fayetteville]

Thanks Guys.. I too suspected the shut off valve. I put a new one in about a years ago. However, I have found that the new reproductions are not often well made and leak. I had a new one in my '30 Townsedan and had to replace it. I have the original one that was in my '31 Tudor. Are the rebuild kits for these any good?

 

[johnbuckley]

One needs to test every shut off valve ... even brand new ones ..they are all suspect.
here's a list of possible leaks from Zeniths
Problem: Remedy
1 Leaking/loose float valve gasket: Tighten/reseal/replace
2 Leaking float valve: (or crud stopping it sealing)Replace ( or clean up if possible )
3 Friction on float hinge: Loosen
4 Incorrectly set fuel level: Re-set
5 Hole in float: Repair or replace
6 Too many gaskets on main jet Check
7 Cap jet or main jet too short: Replace
8 Leaking/loose gasket at main jet: Tighten/reseal/ replace
9 Leaking /loose gasket at cap jet: Tighten/replace
10 Leaking or loose GAV housing threads: Tighten/ reseal/ replace
11 Leak at fuel inlet union: Tighten/reseal/replace
12 Loose/leaking gasket at strainer: Tighten/reseal/replace
13 Loose/leaking gasket at drain plug: Tighten/reseal/replace
14 Cracked housing/leaking passage plugs: Repair or replace

1-7 will generally manifest as poor running.
8-14 will generally not affect running unless there is excessive leaking.

 

[30 Closed Cab PU]

Thanks Guys.. I too suspected the shut off valve. I put a new one in about a years ago. However, I have found that the new reproductions are not often well made and leak. I had a new one in my '30 Townsedan and had to replace it. I have the original one that was in my '31 Tudor. Are the rebuild kits for these any good?

I have had good luck with Brattons shutoffs (guaranteed for 3 years, made in the U.S.), use of the pencil filter in the valve, and running Marvel Mystery oil in the gas. This seems to have solved my issue of valve replacement every couple of years.



The rebuild kits may not necessarily work on the repros, design may be different.


Do a search here on FB, there is a lots of info. Some have good luck buying originals and rebuilding them.

 

[d.]

Nick,
I have done several shut off valves with the Brattton kits and they worked fine.
I used fine valve lapping compound to smooth and polish the innerds before adding the kit parts.
Doug/ Youngsville

 

[cr1248]

I’ve had so many problems with shutoff valves throughout the years that I added another one by the carb.

 

[old31]

CR, please do not take offense but to me that does not look like a real fix, but just another point of failure near the exhaust.

I have good luck with both Brattons and Snyders shutoffs and needle valves.

 

[30 Closed Cab PU]

Old31
X2
If not installed, a cutoff pencil filter to keep trash/grit out of the valve whick scores the ball. Helps a lot. Since installing a Bratton's with a pencil filter, have not had more issues. Brattons - US made, 3 year warranty.


Some say Marvel Mystery Oil in the gas helps lube the valve, I do not use MMO.

 

[Benson]

Re: Zenith carb-EZ TURN GREASE

I have been using and recommending the pencil filter on this and other forums for years.(and Bulletin Board Systems long before the forums got popular).

Found this problem starting in 1970 with dirt bikes out in the woods.

Lots of dirt gets in the gas tank unless you are point man all of the time ... The problem with that is that there are 30 guys behind you trying to run you over to get in front!

My use of the Coupe involves MANY short trips every week for the last 10 years, where I stop and shut off the valve every time.

I would guess it is more than 500 stops in a years time (on/off 1000 times).

The pencil filter helps the valve last much longer but it still lets very fine rust through to get inside the shutoff valve and sooner or later the valve binds up again.

Somebody posted more than fifteen years ago about a fuel proof grease called EZTurn.

1. Clean out the grit and use EZ Turn as soon as it starts to bind up and BEFORE you can not turn the valve. Then you are good to go for a long time.


[ (Leaving the grit inside the valve too long will quickly damage the brass parts of the valve.)

2. Actually I use this grease when installing a new valve ...

Grease is here at Aircraft Spruce:

https://www.aircraftspruce.com/cata...MIuMeO4_-l6gIVUPDACh3KxwqvEAYYASABEgK4AvD_BwE

 

[katy]

Would sticking a rare earth magnet on the outside bottom of the tank catch and hold rust particles? I have a bunch that I "rescued" from old hard drives.

 

[Benson]

Would sticking a rare earth magnet on the outside bottom of the tank catch and hold rust particles? I have a bunch that I "rescued" from old hard drives.

Good idea for small rust particles! Every little bit helps.

From what I have seen MOST rust is attracted to a magnet.

 

[30 Closed Cab PU]

Some do that and report good results. Some will attach a chain or wire to one, and put it inside of the tank, with the chain/wire up through the filler neck for removal/cleaning. If you put it outside you can remove it and clean out the bottom below the filler neck with a magnet on the end of a rod.