Ever have your engine die at a stop light?

You people are awesome. I love it. I've been a member on a number of forums, but never one quite like this. Information here flows like water from a spring.

Coming to a stop and the inherent problems with these carburators might be what I have experienced. I guess that's all the more reason to have the rpms up a little bit when I come to a stop, as was suggested.

The paper filter that I am using very well may be too restrictive. Don't know. So I've ordered a wire filter. I'd like to keep at least the little rocks and grit from getting sucked up into the head.
 
Nex time you have the carb off, run a big file across the two mating mounting flanges. File until all is flat on both the carb and the intake flange. A tiny leak here can cause your prob and this is easy to do. 100% of the flanges must be shiny. Good luck.
 
Jacksonlll said:
Nex time you have the carb off, run a big file across the two mating mounting flanges. File until all is flat on both the carb and the intake flange. A tiny leak here can cause your prob and this is easy to do. 100% of the flanges must be shiny. Good luck.
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IMO


Stalling at stop is not an inherent issue, but is a common issue that can be frustrating to solve, there are many causes. Adjusting the idle lever for stopping is a way to live with the problem.
The problem can be both electrical, or fuel system.
If the issue returns and you want further help, post on this string again.
Before you make up your mind about air filter, use the Search filter on Filter and or Air Filter. The subject has been extensively discussed before. Then decide. It is one of those subjects like "what is the best Oil" A lot of strong opinions.
 
Years ago, I spent the money and bought a properly re-built and tested Zenith carb, and have never had any issues with it....never has stalled coming to a stop, doesn’t leak gas either, even with the fuel line left open.....
 
TerryH said:
Years ago, I spent the money and bought a properly re-built and tested Zenith carb, and have never had any issues with it....never has stalled coming to a stop, doesn’t leak gas either, even with the fuel line left open.....
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That's what I hoped fot when I replaced my old tillison with this rebuilt Zenith 2 last month. The tillison leaked just like this Zenith. I suspect 90% of folks don't inspect their carburtaors after they shut the car down for the day. With both of my carbutators the dripping doesn't start until a minute or two after the car is shut off. I suspect that's when the air stops moving and the heat builds up in the carb. Tested the heat theory scientifically with my hand by touching the carb when the car is running and then several minutes after shutdown. The carb is just a big heatsink on the manifold.
 
Heat build up is normal when you shut off any motor, including the carb heating up, but this should not cause the carb to leak. More than likely what happened is while running, gas usage kept the float in the correct position, and when turned off a very slow leak in the carb overfilled the float bowl which took a couple of minutes. Typical causes are; a float valve that does not seat properly, a bad float, a float valve that does not properly seal/seat in its threads, too high of a float setting, a sticking float, etc.


So are you just wanting additional info, or has the problem reappeared?
 
I think this rebuilt carburetor has a problem also. This morning went out and found a drop of fuel hanging from the bottom bolt on the carburetor followed this back to the intake and all the way up to the Jets. So as suggested the float valve is probably not holding back the fuel. Will check that and probably replace the fuel shut-off petcock for grins. Definitely not lacking in info here. You all have helped tremendously.
 
Without rereading the string again, do not know if it was mentioned. Shim Washers on the float valve sometimes seep. A secondary function of them is sealing the float valve.


What I have found is the shiny shims can be a problem, the red shims seem to work the best. You may not be able to get the exact float level with them that you want, better that the float level using the gauge is slightly lower than higher.


Do not use any type of sealer, it only masks the real issue. Sealer (Teflon tape/dope, thread lock, etc.), can break up/dissolve and plug passages and jets. And if you need to take it apart again, sealer can break off/apart and get into the carb.


A secondary method not using the float gauge is to hold the upper part of the carb body upside down so the float seals the float valve. The solder line of the float should be parallel to the surface of where the float bowl would seat to the upper body. Or if you want to use a different setting, take what you have and measure at the float free end solder line and adjust your shims for that measurement. This way you can get close enough without having to repeatedly take the carb on and off the motor like when using a float gauge.


A quick check is to hold the carb upside down and blow into the carb gas inlet hole, exercise the float up and down and see if it seals. The weight of the float gently seating should seal. This may not tell you if you have a seepage issue.


If you have a hand vacuum pump/gauge you can do a better test by leaving vacuum on the gas inlet with the carb upside down. It should hold for a long time. You also can pretest the valve before putting it in the carb. The pumps are inexpensive, the one I got from harbor freight works good.


I and other have had issues with bad fuel shutoffs out of box new. I now buy them from Brattons. They are USA made, 3 year Warranty. I have also heard that Snyders are good, but do not have experience with them.


One of the issues is rust/grit in the gas tank getting into the shutoff, and gouging the seat/ball of the shutoff. I and others run a pencil filter on the inlet to the shutoff to prevent this from happening. It sticks up into the gas tank


https://www.brattons.com/fuel-tank-filter-screen.html
 
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