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Angelo

Junior Member
I am having a lot of difficulty seting the float. No matter what the carb overflows. I have removed the bowl with the carb on the car, turned on the fuel with my thumb pushing the needle into the seat and the fuel stops. I have checked the float for leaks and it checks ok. I believe that I am not setting it corectly. Does anyone have the correct measurement for float height on a Tillotson F-1B??? The book I am referencing is not very detailed when it comes to float setting.

Thanks in advance,
Angelo
 
I don't know about the F-1B, but, I think all Tillotson floats are the same.. The only info I've found for the float height is 1" [ top base with no gasket to top of float], but, mine run better at 3/4".. As far as the leak goes, they tend to do that.. Look at the float arm for a little dimple where the needle makes contact , sand/emery the arm till the dimple disappears.. See if that helps..Which needle do you have[solid or rubber]?? 'They' claim that the newer viton tip needle is less likely to leak..
 
I cant see what the needle sets against but I think it just seals against brass, its a one peice brass needle and seat that threads into the carb.
 
The metal to metal needle and seats are very difficult to keep from leaking. If one is available, I suggest that you purchase and install a Viton needle. I have been using them in my Zenith carbs with great success. Gar Williams
 
Tillotson: Models F-1B, X, and XF

  • "Restorer" magazine, Jul/Aug 1995, Page 12, "Tillotson Carburetors"
  • "Skinned Knuckles" magazine, Aug 1985, Page 14, "Rebuilding Tillotson Carburetors"
  • "Restorer" magazine, Jan/Feb 1999, Page 4, "Tips for Restoring Tillotsons"
  • "Restorer" magazine, Jul/Aug 1995, Page 23, "Curing Tillotson Gas Drips"
 
Save yourself some time and headaches. Get the clear tube that mounts to the bottom of the carb that shows you the fuel level. Then you can adjust the float as needed. I set my F-1B just like the Model X. 1". Click here to see an example.
 
Angelo said:
I am having a lot of difficulty seting the float. No matter what the carb overflows. I have removed the bowl with the carb on the car, turned on the fuel with my thumb pushing the needle into the seat and the fuel stops. I have checked the float for leaks and it checks ok. I believe that I am not setting it corectly. Does anyone have the correct measurement for float height on a Tillotson F-1B??? The book I am referencing is not very detailed when it comes to float setting.

Thanks in advance,
Angelo
Click to expand...
I would remove the needle valve and seat. I would then put some tooth paste inside the seat and work the needle back and fourth. This will allow the fine abrasive action of the tooth paste to smooth any rough spots on the needle and seat that may be causeing problems. Clean off all traces of tooth paste and now will be a good time to clean and blow out the jets and passages. I use the carburetor cleaner that WalMart sells in spray cans and then blow out with compressed air. I would remove and clean out the filter screen that attaches in the front of the carburetor. I would turn the top of the carb upside down in my hand and observe the position of the float. I never measure but just set be eye. The float will probably have a seam where it is put together, I usually sight off the seam and adjust the float so that the float is almost level. It is usually best to adjust the float just a very small amount lower than level towards the bottom. this will allow the needle valve to cut off the gas flow just before the float is level and keep the fuel level from rising TOO high in the bowl of the carb. The best way to adjust the float is to add or subtract washer-gaskets under the seat, this will raise or lower the float without haveing to bend the float hinge.

As far as I know there is NO parts produced for the F-1B carb. Some Zenith parts can be used such as the float , GAV assy, and with a little modification, the gaskets. I'm not sure about the needle valve assy. The F-1B looks very simillar to the Zenith but being as it is made of pot metal, there is a good chance that the flange will be warped where it meets the intake manifold. You can lay the flange on a flat surface and if there are any small gaps around the circumfrence of the flange this will indicate warpage. Any warpage in the flange wuill cause vacume leaks and VERY POOR performance. Usually the main problem with the F-1B carb. is that the small passages become blocked. I think that Mr Texas is probably the guy with more experience with these carbs. I saw where he posted here a couple of days ago on a thread about Tillotson carbs. If all else fails I would search and try to contact him for other pointers. I think he was offering to send out exploded diagrams an info on these carbs on the ford barn a couple of years ago. Good luck and keep us posted.
 
Angelo said:
I am having a lot of difficulty seting the float. No matter what the carb overflows. I have removed the bowl with the carb on the car, turned on the fuel with my thumb pushing the needle into the seat and the fuel stops. I have checked the float for leaks and it checks ok. I believe that I am not setting it corectly. Does anyone have the correct measurement for float height on a Tillotson F-1B??? The book I am referencing is not very detailed when it comes to float setting.

Thanks in advance,
Angelo
Click to expand...

From what you said, you know the needle valve works. Ir should seal with very light upward finger pressure against the gravity fuel in an A, just ten grams if you have a fine spring scale. Hopefully it is not a grose-jet valve with the two metal balls. They like to hang up. You should have a standard steel pin.

Something is preventing the float from easily moving the pin. There should be no worn groove, divot, or rough spots on the engagement tab, the base of the pin, or the float pivot/ hinge. If the float is bent slightly off-center it can scrape the side of the bowl when assembled and hang up.

I wouldn't be in a hurry to put in a viton-tip valve. If you do replace the valve, use another steel pin valve. The viton tip valves tend to stick to the seat, especially when parked hot and allowed to cool off and sit for a few days. Cars with fuel pumps have no trouble popping them open, but an A with 1/4 tank and gravity may require you to rap sharply on the carb to free it.
 
These metal needles seal best if the float is pushing them straight up and not to the side. If yours is pushing the needle to the side, you will need to bend something on the float.

Rotating the needle while pushing in with pliers helps to reduce or eliminate a leak. Some people say to rotate with a drill motor, but I think that to be too much.
 
I found, at least with the Zenith, that for a long time A parts dealers were advertising " install the gross jet float valve and stop your carburetor from leaking".
The ball in the gross jet valve is only a few thousnads above the ball cage; if not careful, the float will bottom on the cage and not apply pressure to the ball; hence, a leaking carburetor, usually over the top of the main and cap jets.

Ron
 
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