Tillotson carb

MickyD

Senior Member
I had it rebuilt last year and it leaks internally. It did leak at the top seam but that has been fixed. It runs great except for the small leak. I checked the float and measured fine. I am confused about what to do next.
 
Find a Zenith. There are lots of them and they aren’t expensive. Tilly’s are notorious for warping and leaking.
 
Just where is it leaking ? Tilly's are good carburetors when in good shape. I think they run better than Zenith, but, not quite as nice as Marvel's.

The float can be set correctly, but, the needle may not be seating correctly/fully. There are several types of needle/seats, which do you have ?
 
Micky -

I agree with Patrick. Tillotson runs very well. I cannot argue that the Tillotson is better than Zenith because I have never had a reason to change or a Zenith to compare.

Our 1930 Coupe came to the family in 1957. It was equipped with a Tillotson and a spare Tillotson in a box of assorted parts. I completely rebuilt the engine in 1965.

Over the years, I have rebuilt each the two Tillotsons a couple of times.

The only times that I experienced leaks were when I did not get even pressure on the top screws and once when I had a bad float valve.

Tim
 
Tilly's are good carbs. Like Patrick said what type of float needle do you have. Buy a viton tipped float valve they work better with the corn gas we have to use today.
 
Get a Zenith and move on.

Years ago I tried to work with the Tillotson on a 31. It was just not worth the effort. Changed to a Zenith, never looked back.

Our 29 has never had a leaking carburetor in 41 years. Zenith. Easy to service. One less thing to worry about.

Enjoy
 
Gee, let's talk about what oil Micky should use! That's worse than politics.

Just after the carb was rebuilt did it leak, or is this something that just started?

A tilly will out perform a Zenith any day. No reason to change. As noted above try a viton tip needle and see what happens.

When you say you checked the float, what did you check? Shake it and see if there is anything inside of it. Check the float level so that it is 5/8", you will need a gauge for that.

https://www.snydersantiqueauto.com/...FUEL-LEVEL-GAUGE?fromCategory=SearchByKeyword
 
I recently bought a rebuilt Tillotson and it works well. No leaks or other problems. Like TN Hammond, back in the 60's boxes of spare stuff was easy to acquire and in a box came spare carburetors, including a Tillotson. I put it on my stock Model A coupe and thought that it performed better, including better idle and improved torque, but the opinion was subjective, not based on any testing data. I eventually went back to the Zenith for some forgotten reason. I now think that the Zenith and the Tillotson are fairly equivalent, given that they both are in good shape. But, again, this is subjective and not based on any data.

The major advantage of the Zenith is that it is cast iron not pot metal.
 
Gee, let's talk about what oil Micky should use! That's worse than politics.

Just after the carb was rebuilt did it leak, or is this something that just started?

A tilly will out perform a Zenith any day. No reason to change. As noted above try a viton tip needle and see what happens.

When you say you checked the float, what did you check? Shake it and see if there is anything inside of it. Check the float level so that it is 5/8", you will need a gauge for that.

https://www.snydersantiqueauto.com/...FUEL-LEVEL-GAUGE?fromCategory=SearchByKeyword

Old31, the float gauge you linked to is for a Zenith. Will it fit the Tillotson? Rennen's Corner has one for the Tillotson (and Marvel). https://rennerscorner.com/carburetor.html

To fix the warping, I fixed mine by baking in the oven at 250 degrees with "C' clamps!

After you get it flat, do not over-tighten the screws when reassembling. I only tighten the screws enough to flatten the lock washers, no more. As mentioned in another thread, I also cut my own gaskets out of .031" Cork/Buta-N. It is softer than the paper gaskets included in the kits and conforms better to seal. Use no sealant!
 
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Yes, the zenith gauge will work but not as good as renners due to the shape of the tube. Go with Renners, he is a great guy to work with.

A-9599-TL
Description: TILLOTSON X XF CARBURETOR FUEL LEVEL SETTING GAUGE
Comments: High accuracy to set the float - fuel level / instructions included
Application: 1928 - 34
$16.00
 
I took the top off the carburetor and it looked to be 1" from the top. I am still looking to see exactly where the gas is coming from.
 
There are two external plugs in the Tillotson from drilling the internal passages.

Zenith also has two, but they are brass so less likely to leak. I would guess the original Tillotson plugs were a Pb lead alloy for a good seal, but maybe on rebuild a more Environmental alloy was used so they are more prope to leak on heat cycling.

I've seen these plugs leak on modern carbs too, notably the Autolite 4300 Carb on a hot (over 200F) engine with a lot of heat cycles. It can be hard to find because if you do a bench test, the carb wont leak (of course not!). But then put it on the car, and after use it will leak.

Jet gaskets are another culprit.
Either way the whole carb will slowly empty out.
In a way that's good, then the Corn Gas doesnt dry out inside the carb, but leaks arent really the best way to make that happen!
 
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