Problems after carb rebuild

[Jim Arm]

I think I have gotten the needle valve leak under control. It will leak a little over night but not enough to cuse running problems.
Now it might start easily and run nicely for five minutes or so.
Then stopping it means no restart. Tuens out that the carb is thoroughly flooded at this point, dripping from the overflow hole and with all plugs soaked.
I think I have tried every suggestion you folks have offered.
I have had it off the tractor and on the bench a dozen times.
I have rebuilt 20 or 30 carbs of all kinds over 70 years. I am in no hurry and know it will work again.
More ideas are welcome.
PS: Wouldn't water in the gas show in the sediment bowl? And wouldn't the reserve system keep it out of regular valve opening level?

 

[used red MN]

I think I have gotten the needle valve leak under control. It will leak a little over night but not enough to cuse running problems.

DO YOU?

Then stopping it means no restart. Tuens out that the carb is thoroughly flooded at this point, dripping from the overflow hole and with all plugs soaked.

OR DON’T YOU?
Aside from the test soaked shows in reply 6, in my mind one of the best ways to check for float needle seal is by mouth vacuum. It might be a bit unpleasant since the parts have already been exposed to gas. To remedy this you could soak/boil the top of the carb in a soap solution like Simple Green. The vacuum test is as simple as this, much like as when you played with a straw holding your finger on the bottom and your tongue on top holding vacuum in it. Assemble the carb top with the float on it. Hold it with the float up so its weight is closing the float valve. Suck on the fuel inlet port and seal the vacuum against it with your tongue over the connection hole. The vacuum in the fuel inlet port should be easily held against the float needle valve 5 seconds. If it doesn’t hold you have to find out why. Coining which is essentially “reseating” the needle seating surface in the brass seat may be required.

 

[560Dennis]

Suggust this tip, testing the float ,put in refrigerator get it cold . Plunge it into warm water and look for leaks. Got this tip McDonald carburetor.

 

[soaked]

I think I have gotten the needle valve leak under control. It will leak a little over night but not enough to cuse running problems.
Now it might start easily and run nicely for five minutes or so.
Then stopping it means no restart. Tuens out that the carb is thoroughly flooded at this point, dripping from the overflow hole and with all plugs soaked.
I think I have tried every suggestion you folks have offered.
I have had it off the tractor and on the bench a dozen times.
I have rebuilt 20 or 30 carbs of all kinds over 70 years. I am in no hurry and know it will work again.
More ideas are welcome.
PS: Wouldn't water in the gas show in the sediment bowl? And wouldn't the reserve system keep it out of regular valve opening level?

Yes, water in the fuel should be settled at the bottom of the glass bowl before running the engine. Some amount of gas or water may get past the shut off valve threads, red line is reserve. (At two turns out, the threads on the valve would block the reserve port)

In post # 18 you stated the leak was 10ml in 24 hrs.
10 ml of gas is about 200-250 drops.
In 24 hrs that's about 8 to 10 drops an hour, or about .14 to .17 of a drop in a minute.
Is that what you're seeing?
If only a few minutes go by then try restarting, the drop wouldn't have fell, so flooding is from some other source, at least to me.
Float hanging up, or even weak spark or ????

 

[used red MN]

Yes, water in the fuel should be settled at the bottom of the glass bowl before running the engine.

My question is what part does he think water is playing in his problem?

 

[soaked]

My question is what part does he think water is playing in his problem?

I dunno, perhaps he saw droplets in the carb air intake, after it flooded (indicating water)

 

[Jim Arm]

Without definitely knowing the cause of my problems, they seem to have resolved.
It will be several more tests over a few days to be sure, but I am hoping they don't return.
It may be running smoother than it did over most of forty years, but being able to retain the reliability I counted on will be the key.
Strangely in the middle of the process I lost oil pressure and had to prime the system to get it back.