Zenith Carb Jet Gaskets?

[DaWizard]

Something that I am wondering....

After rebuilding a few Zenith carburetors I have found another source for what I would call "spacers" for use on adjusting the height of the Cap and Main Jets.

My question is, are the gasket/spacers used to set the height of these two jets also used to seal the threads to the carb body, or can something else like a steel "washer" be used against the jet and the fiber be used to seal off the threads?

Now, I know that the dimensions for the spacing of these jets is in fractions, so with my background that would mean unless listed on a blueprint it would be +- 1/32". But since I use a finely tuned and certified measuring device, I would try to adjust the distances to within a minimum .001, and I can do this with the steel spacers I have at hand. Now it may be that the +- 1/32" is close enough, but hell, I'm anal and can adjust it closer providing the fiber washer is against the body for the seal and the steel against the jet for distance.

Any thoughts, or just tell me I'm anal and the 1/32 is close enough.

[Mitch]

How about setting the Cap Jet @ 1/16th below the lower casting that the venturi sits on

The Main Jet should be level with that same casting

If you wanted to be more precise than when they built them at the factory a steel washer with a fiber should work IMO.. Copper maybe better

[Dennis]

Doesn't make any difference what material you use as long as it will seal between the surface of the valve to the surface of the body.

[H. L. Chauvin]

In trying to anal-lyse leaks with carburetor steel spacer washers, it appears that the key to preventing gasoline leaks is to always maintain contact of any metal to a carburetor fiber washer, as opposed to metal to metal contact where a metal washer contacts a metal carburetor body. Metal washer to metal carburetor body would seal as well as a metal oil pan in contact with a metal cast iron engine block without a gasket.

If the fiber washer contacting the metal carburetor jet and contacting the metal carburetor body does not leak gasoline, gasoline cannot penetrate this gasket and contact the metal jet threads. For example, the gasket on the oil pan works the same way where the oil pan gasket seals these joints such that oil does not get to the oil pan bolt threads.

Might also be advantageous to anal-lyse Bratton's note written under his gasket set part no. 13820 where he changed gaskets to nylon as opposed to the leaking red paper washers which get soft and leak profusely after a short time.

This hint may not solve all carburetor gasoline leaks, but at least it sounds anally interesting to maybe try Bratton's non-leaking nylon washers to try to prevent carburetor leaks.

[Mike V. Florida]

Steel, water in gas = rusted spacer?

[Mitch]

True

[H. L. Chauvin]

Addition to Model A Gaskets 101: Not to change the subject and location of possible gas leaks from the carburetor jet etc.; however, many former Model A Forum guests in the past condemned using the late 1929 to mid 1931 glass sediment bowl because of constant sediment bowl gas leaks.

Later non-Ford reproduction sediment bowl screens offered were too large in diameter and did not fit down into the sediment glass bowl recess; hence after sediment bowl assembly, there was perforated metal screen to upper metal contact ....... or, perforated metal screen to lower glass bowl contact ..... as opposed to gasket contact to upper metal and gasket contact to the lower glass bowl.

With these larger diameter screens offered, (and as late as 10 years ago,some were still found to be too large in diameter), I used to use a scissors to trim the metal screen so it could neatly fit down into the glass bowl recess.

Results: Never had a glass sediment bowl leak in 50 years.

"Never a bad idea to realize that today's different ethanol gas can be unpredictable when in contact with yesterday's old reliable vintage gasket material."

[Tom Wesenberg]

Years ago I used to save the automatic tranny filters when I serviced them. Many had a nice fine brass screen that I'd cut out and save for fuel filters or anything else that needed a fine screen. And, as Henry mentioned, be sure it fits in the recess, and not out to the edge of the glass.

[H. L. Chauvin]

When buying my 1930 Coupe in 1958 for $25.00, the very kind former owner and neighbor showed me why to never omit the sediment bowl screen filter ...... he removed the screen filter, placed water on it, and even minute drops of water would not pass through the tiny holes in this screen filter.

Next he showed me that when water could not pass through the sediment bowl screen filter, water from the gas tank was noticeably encapsulated at the bottom of the glass sediment bowl, with gasoline floating on top whereby accumulated gas tank condensate water could not get to the carburetor.

I soon realized that this vintage mechanic was really an analytical genius.

[Tom Wesenberg]

Henry brings up a good point about the fine brass or stainless screens blocking water. My red plastic gas cans with the yellow spouts have a brass screen, and they also block water flow. I learned this when the crap gas came on the market and enough water was absorbed by the ethanol to block fuel flow out the spout. The crap gas soon disintegrated the brass screen however, so it was a short lived benefit.

[H. L. Chauvin]

Tom,

I bought a new gas tank filler screen about 10 years ago, next filled up with ethanol gas, and the ethanol gas appeared to have solidified my gas tank filler screen with an encrusted, solid white material such that gas would barely pass through the orifices in filler screen.

Wouldn't surprise me if some ethanol gas has a small percentage of experimental Imodium ingredients mixed in with it to create blockages.

[Mitch]

When buying my 1930 Coupe in 1958 for $25.00, the very kind former owner and neighbor showed me why to never omit the sediment bowl screen filter ...... he removed the screen filter, placed water on it, and even minute drops of water would not pass through the tiny holes in this screen filter.

Next he showed me that when water could not pass through the sediment bowl screen filter, water from the gas tank was noticeably encapsulated at the bottom of the glass sediment bowl, with gasoline floating on top whereby accumulated gas tank condensate water could not get to the carburetor.

I soon realized that this vintage mechanic was really an analytical genius.

Henry that is a good informative post. Can you copy and paste that to this thread for me. It would be a nice addition to this fuel filtering tech thread

https://www.vintagefordforum.com/for...tering-options

[H. L. Chauvin]

Hi Mitch, Copied & pasted as requested.

[Mitch]

Thank you Sir

[Dennis]

That has me wondering if that was part of my problem recently when my car started to act like it was running out of gas after 30 miles driving, sometimes less. Always filled up with gas and forgot about adding a little MMO. I started dumping MMO at an increased amount of 6 oz per 10 gal. Problem seems to be going away.