Carter YS carburetor - flooding when idling while driving

1952 - 1968, M38A1, M170, questions, discussions, regarding anything related to the M38a1 series.
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1000Fuss
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Carter YS carburetor - flooding when idling while driving

Post by 1000Fuss » Wed Aug 27, 2014 10:24 am

Hey guys, here is a problem that gives me a hard time finding a solution:

Sometimes (not always) when I take out my jeep for a ride, I get off the accelerator pedal to keep the car just moving with the engine idling, i.e. when I approach a red light. A few times the engine floods in those moments and I can not get it back running. Usually I take off the carburetor, drain it, disassemble the three parts, clean all of them, blow them out with some compressed air and assemble everything back again, just to install the whole unit on the engine. Back in good shape, the carb takes up its duty as expected.

As you can imagine, it isn't really satisfying never to be sure if you get back from a ride without being towed.

So here is my question: does anyone face the same problem? Do you have an idea where to start looking at? Is it the float not closing with its needle? Is it the gasoline or the vac pump?

FYI - except those flooding moments, the engine usually runs smoothly.

Thanks for sharing your thoughts with me... :wink:
1956 M38A1
1951 CJ-3A project


gianjeep
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Re: Carter YS carburetor - flooding when idling while drivin

Post by gianjeep » Wed Aug 27, 2014 10:53 pm

checks floating bowl for crack or hole,
or sometime the lip became too soft and the petrol pressure into the bowl can force it to bend up,
or fuel pressure too high,
or malfunction in fuel pump(release valve),
or inadeguate fording pressure,
hope this help regards Gian
ford gpw,6/1942
m38,5/1952
m38a1,7/1954
cj5 232 i six 4/1971

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Re: Carter YS carburetor - flooding when idling while drivin

Post by Jeeps4Brains » Thu Aug 28, 2014 3:56 am

If you have junk floating in the fuel it can get stuck where the check valve is where the fuel comes into the carburetor.

Then no matter how much the float tries to close that valve it can't and gas just keeps pouring in.

When it does that can you turn the gas off to the fuel pump and then try to start the engine? If you can get it to start and run the carb dry then when you open the gas valve again and run the engine, there is a chance the gas rushing in the wide open check valve will clear it.

It worked for me when mine was flooding in the same manner.

Alan
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Re: Carter YS carburetor - flooding when idling while drivin

Post by Joe Gopan » Thu Aug 28, 2014 4:56 am

The Diaphragms could be a contributor due to age. One other not to those who remove the carburetor for inspection. It is easy to lose the Pump Discharge Check Ball and it's weight when inverting the float chamber (Carburetor body. The weight is that small rectangular object that rests on the ball.
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Re: Carter YS carburetor - flooding when idling while drivin

Post by 1000Fuss » Wed Sep 17, 2014 9:45 am

Thanks for all your input!

I run a rebuild set on the fuel/vac pump. It seems that the carb gets the right amount of gas now: no more blue smoke from the exhaust pipes.

I will double check the diaphragms because the carb now has problems switching from one form of load/speed to another. Idling is okay. The engine floods when running on a high level and than changing to less...
1956 M38A1
1951 CJ-3A project


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