Leaky Carburetor Inlet Valve

Before parts suppliers got on the ball and started making good reproduction parts, a dripping carburetor was a common sight. We still see this condition where it is impossible to remove the needle seat, and in the case of the early type carburetors, some of these have a peculiar type of valve, some do not have a replaceable seat, and the rest do not create a sufficient demand to justify tooling. The most popular solution to the problem has been to install a shut off valve in the gasoline line near the carburetor. Most of the 1926 & 27 models already have a valve accessible under the hood. Whenever the car is stopped, the owner would lift the hood and shut off the gas. Some owners would leave the hood up as a reminder to turn on the gas when ready to go again.

Suppose that you are faced with this problem when neither a replacement needle or a Grose Jet is available. Here is what you can do: the original needle with three flats may be chucked in a drill press. Use a file on the spinning needle to re-establish the original core shape and eliminate the existing groove. When this has been done, place the needle in the carburetor in the needle seat and tap it lightly with a hammer. The object is to make the reworked needle conform to the seat without creating a new deep groove. Test by turning the carburetor upside down and applying suction to the inlet fitting. It should be possible to hold a light vacuum for fifteen seconds. If it fails this test, repeat the hammer tap operation use a bit more force, retest, and repeat as necessary.

The same procedure is recommended when a new needle and seat are installed. I have found that this works, but it does require care and patience. (Hugo Richter, October 1984

Leaky Gas Line Connections

It seems that just about every Model T has a small leak in the carburetor or the sediment bulb. While I addressed a leak around the threads of the sediment bulb in an earlier issue of a T-Time, the problem of the needle and seat in the carburetor and the "tapered" shut-off on the sediment bulb was not addressed. These two areas have a tendency to leak because of wear and dirt. I've found that "lapping" the needle and seat and the shut-off valve and the sediment bulb body with a mixture of oil and baking soda (YES, baking soda!) stopped even the slightest leaks. I also tried thinning down toothpaste with water, yet found this compound was TOO harsh and the leaks continued. If you have an early brass carburetor, lap the metal needle into the seat and then replace the metal needle with a neoprene needle. It will never leak again!!!

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One of the aggravating problems with a Model T is a fuel leak. One of the most common fuel leaks can be found where the sediment bulb is screwed into the gas tank. I have found that Teflon tape can be used successfully, but this is not a guaranteed repair. A permanent repair can be accomplished by filling the threads on the sediment bulb with solder. First, remove the sediment bulb and thoroughly clean the threads on the bulb which screws into the tank. Next, once the threads are clean, "tin" the threads with solder. While the sediment bulb is hot, fill the threads with solder and then quench the bulb with warm water. If you have a power wire brush wheel, remove the excess solder so the top of the threads can be seen. Now screw the bulb back into the gas tank and any leaks should be a thing of the past. (Author unknown, From T-Time in CanyonLand ~2000)

To Prevent Engine Running Too Fast or Choking with Throttle Retarded

If the engine runs too fast with the throttle fully retarded, unscrew the vaporizer throttle lever adjusting screw until the engine idles at suitable speed. If the motor chokes and stops when throttle is fully retarded the adjusting screw should be screwed in until the proper adjustment is obtained. (Ford Instruction Manual)

Repairing a Cork Float in an Early T Carburetor

If you rebuild an early T carburetor, you normally will find the cork float is dry, warped and sometimes broken. At this point we think it would be easier to just find a similar brass float from another carburetor or find another complete carburetor rather than to repair the cork float. But hold on to that float, there is an easy AND fool proof method of repairing this little piece of cork and once the repair is made, you will never have any further trouble with the float.

The only stipulation is that the float must be able to be glued together and be complete. If the float is broken, it can be glued back together using regular white glue (like Elmer's glue). Let it dry overnight. If the float is warped, try to straighten it out by pinning the float to a flat surface, and once the glue has dried, it will remain straight. Next, go to your local hobby shop and purchase model airplane dope (the color doesn't matter, but I've been told that red makes a T go faster). You will need enough dope to submerse the float in a one pound coffee can (about one inch of dope in the bottom of the can works fine). Put a wire through the brass loop that holds the float to the carburetor and place the dry float into the dope. The dope is lacquer based so be careful of the fumes. Once you have submerged the float into the dope, take the float out and let it air dry. Do not let dope get on the wire, or the brass loop as this will cause the float to stick in the carb, just submerge it far enough to cover all of the cork. Dip the float at least two more times. With three coats of airplane dope, you have effectively sealed the cork float. The dope is very light and gasoline has no effect on the dope. (From T-Time in Canyon Country)

Adjustment of Vaporizer

The usual method of regulating the vaporizer is to start the motor, advancing the throttle lever to about the sixth notch, with the spark retarded to about the fourth notch. The flow of gasoline should now be cut off by turning the vaporizer adjustment rod to the right until the engine begins to misfire, then gradually increase the gasoline feed by reversing the adjustment until the motor picks up and reaches its highest speed and no trace of black smoke comes from the exhaust.

Use care in adjusting the vaporizer as turning the needle down too tightly will result in its becoming grooved and the seat enlarged. When these parts are damaged it is difficult to maintain proper adjustment of the vaporizer. (Ford Instruction Manual)

Carburetor Priming Wire

The carburetor priming wire, which controls the choke, costs very little. Yet it is a nuisance to have it break off at the carburetor, as it usually does after having been taken off and replaced a few times. It is also a little troublesome to introduce it through the hole in the radiator shell.

Simply cut the wire in two, about midway, while in position on the car, and join the cut ends of the wire together with a small electrical wire connection (procurable at any electrical store), consisting of a little brass tube with four screws in it. The ends of the wire slip into the tube from each end and are held by two screws each. To remove choker wire from radiator simply loosen two screws and pull wire straight out -- with no bending or trouble.

Another advantage of this connection is that it allows you to thread a common lead pencil eraser on the choker wire, so that the rubber will butt up against the front end of the radiator apron and take all rattle out of the choker wire. The exact pressure required is easily arranged at the connection. (From the T-Bone Times (19?)

Cleaning the Vaporizer Heating Plate

Approximately every five thousand miles it is advisable to remove and clean the vaporizer heating plate. This plate can be easily removed by removing the four exhaust manifold cover screws, loosening the vapor outlet tube nut and moving the cover away from the manifold. (Ford Instruction Manual)

Float – Balsa Vs. Cork

I recently made a float for a model G Holley carburetor. I used balsa wood instead of cork and have gotten good results. I coated the float with clear airplane dope (which has a lacquer base). (Nolan Renfro 1982)

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