Zenith Fuel inlet- Ball or Needle Type?

[29restorod]

I am getting ready to tackle my stalling under braking problem. I purchased a double ball type inlet,and a new float from Snyders. I was hopeing the ball type inlet was an improvement. Any opinions?

[Tom Wesenberg]

The needle and seat simply cuts off the gas when the bowl is full enough. I think you'll find you need to adjust the height of the fuel in the bowl. That seems to be the most common fix for stalling while braking.

My engine slows considerably while braking, but runs fine otherwise, so I'm leaving it as is. I haven't tried real hard braking to see if that would kill the engine, but as long as it doesn't stall under moderate braking, I'm fine with that.

[TinCup]

I have used all three different types of float valves. When I have had problems with either the viton tipped or the double ball valve it has always been because of debris from the gas tank. They are easily cleaned but an annoying failure.

Tom is dead on about the braking problem. Float is set too low and when you brake the jets are starved for fuel.

[Patrick L.]

I like the 'Grosse' style valve.. I'm not impressed with the viton tipped needles with a gravity feed system.. It seems as thought they should work well,but, they are the only ones I've had trouble with..

[Jerry Parr WI]

Originally Posted by Patrick L.

I like the 'Grosse' style valve.. I'm not impressed with the viton tipped needles with a gravity feed system.. It seems as thought they should work well,but, they are the only ones I've had trouble with..

My experience has been the opposite. The Grosse valve I tried would fail to stop the gas on occasion and the carb would leak. With viton valves I leave the gas turned on year round including winter storage.

[Mitch//pa]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by Jerry Parr WI

My experience has been the opposite. The Grosse valve I tried would fail to stop the gas on occasion and the carb would leak. With viton valves I leave the gas turned on year round including winter storage.

same here except i always turn off the gas as a precaution......

my vitons have been working so far with ethanol

[Purdy Swoft]

To address the stalling apon brakeing problem, I agree float setting is the problem! Not to confuse my explanation by saying that the float is set too high or low, the problem is too much fuel in the carburetor bowl. When the brakes are applied the gas will slosh backward flooding the carburetor and the engine will stall. The description High or low depends on how you are looking at the float. I determine the setting while holding the upper half of the carburetor upside down in my hand. some say the measurement is 5/8 from the upper gasket surface to the seam where the float is joined together and this is about correct. With the upper half of the carb held upside down the float seam needs to be slightly below level as it would be when mounted on the car so as to lower the level of the fuel in the bowl. I never measure the level, I set them by eye. People having stalling problems need to experiment and after a couple of tries you can develop the technique of setting the float by eye. If the float is set in such a way that the fuel is too low in the bowl the carb will starve for fuel and backfire apon acceleration much like if the gav is closed too much. If the level is too high in the bowl the carb will leak and stall apon brakeing. Its not that high tech. I have used the ball type float valve in some of the model B carbs that I use with good results. The last few model A zenith carbs that I rebuilt, I used the original type float valves with good results. I tap the needle with a hammer to better seat the needle to the seat. I always prefer to adjust the float level by adding gaskets under the seat. Sometimes the original floats have been bent to adjust. I have at times tried bending them back to a more favorable position to save a float that is otherwise good and not leaking.

[1931 flamingo]

I adj my float (had to replace it) and now no more stalling when stopping.
Paul in CT

[cars56]

Same issue here
This is what solved it: 2 white neoprene float valve gaskets stacked on top of each other and a new new square float valve. Both purchased at Bert's

[29restorod]

I am getting a little confused as to what the float measurement should be. One person says 5/8" upside down,and measuring from float seam to gasket surface. Someone else posted 1" using the same meathod. Mine is now set at 15/16",and stalls every time I take my foot off the gas. When I got the car it had one fiber gasket,and one clear plastic washer under the needle. I removed the plastic washer,which raised the fuel level,still no change. If I can find another washer,I will try two washers,and see what happens.

[Purdy Swoft]

The one inch float setting is for the Tillotson model X and XF carbs!!! If it stalls when you take your foot off the gas, you have other problems, maybe with the idle curcuit. It could be the idle jet. I would also check the port near the throttle butterfly that leads to the idle jet, sometimes this opening will be blocked. I use a small torch tip cleaner smaller than the opening. If the float is actually set at 15/16 and you add another washer, it will only get worse!!!

[29restorod]

I am very happy to say, I cured my stalling problem tonight. I was so sure that the float level was the problem,I did not check out the rest of the carb good enough. I tried one more time,even though I had no spare parts on hand. I started checking passages with a torch tip cleaner. I could not get any air through the idle jet. The smallest tip cleaner was the right size for the small end. I could feel something crunch as I inserted the cleaner,then I could blow air through it. Put it back together,and I could now retard the throttle lever all the way,and slow down the idle speed,with the throttle screw. The road test was amazing,I am loving all the memmories of my old Model a from 1960. I am duplicating my old car,with 16" 35 wheels,hydraulic brakes,turn signals,and simple non stock upholstry,and a few engine mods. In 1961 the restorers called me a "Hot Rodder" and the Hot rodders called me a "Restorer".I was an out cast. Today both groups seem interested in my car.

[Purdy Swoft]

I'm glad to hear that you've solved the problem, thanks for letting us know what the problem was.