John Deere 225z 18.5 hp wont run

[halwynn]

The mower just suddenly cut off while I was mowing, like it had run out of gas. I have replaced all of the gas in the tank and lines. I have checked to make sure that fuel is getting to the carburetor. I have taken the carburetor apart and cleaned it. I have bypassed the seat switch to be sure it was not cutting the mower off by not working.

It will fire up when I try to start it and run for a few seconds and then cut out. It's like its not getting gas, but I'm sure there is no debris in the carburetor.

I'm wondering if another cut off switch could be causing a problem and disrupting the flow of fuel to the carburetor?
I would suspect the fuel pump, but when I turned the motor over and took it off the carburetor, it seemed to provide a plentiful supply.

I have a feeling it is something simple, not major, the motor is only about 3 years old.

Thanks for any suggestions.

 

[KennyV]

WELCOME to these Forums...

You need to determine if you are loosing ignition or Fuel.
The simplest way to check is use a substitute fuel... Spray starter fluid or carb cleaner directly into the carb when it starts to die... If it will continue to run with the spray it has ignition.
Post back with your results.... :smile:KennyV

 

[halwynn]

It did run some while spraying starter fluid in it, so I know it is a carburetor problem. I replaced the carburetor, but now when I try to crank it, it is bound up, and will not turn over. I took the plug out and fuel gushed out of the plug hole. I then turned it over with the starter and fuel gushes out of the plug hole. When I had it running a little before replacing the carburetor (I cleaned the old one up first and tried to make it work, but it would only run rough), it was running rich, blowing out some black smoke and would need to be cranked at a low idle position. So I figured the problem with my carburetor was that the mixture was too rich. Now, I'm wondering if I have a blown head gasket or a valve problem. What would allow so much fuel at the top of the cylinder?

WELCOME to these Forums...

You need to determine if you are loosing ignition or Fuel.
The simplest way to check is use a substitute fuel... Spray starter fluid or carb cleaner directly into the carb when it starts to die... If it will continue to run with the spray it has ignition.
Post back with your results.... :smile:KennyV

 

[KennyV]

Great your on the right track... Carburetor.

The float needle valve assembly is not regulating fuel flow to the carb.
This is a common problem, and has only a few causes.
Start at the float in the float bowl. Is it damaged or stuck?
How about the needle seat are they able to shut off the fuel when the level is correct?
Check these things out because That is where your problem is likely originating.
Free flowing fuel Will run into the carb and go directly into the combustion chamber, It Also will get into the engine oil... So be sure you Change the oil... gasoline will destroy the oil.... :smile:KennyV

 

[PapalVisit]

The mower just suddenly cut off while I was mowing, like it had run out of gas. I have replaced all of the gas in the tank and lines. I have checked to make sure that fuel is getting to the carburetor. I have taken the carburetor apart and cleaned it. I have bypassed the seat switch to be sure it was not cutting the mower off by not working.

It will fire up when I try to start it and run for a few seconds and then cut out. It's like its not getting gas, but I'm sure there is no debris in the carburetor.

I'm wondering if another cut off switch could be causing a problem and disrupting the flow of fuel to the carburetor?
I would suspect the fuel pump, but when I turned the motor over and took it off the carburetor, it seemed to provide a plentiful supply.

I have a feeling it is something simple, not major, the motor is only about 3 years old.

Thanks for any suggestions.

Could be vent on fuel cap is clogged.

 

[halwynn]

Could be vent on fuel cap is clogged.

The problem was simply a fuse for the fuel relay switch. Now it runs great.

Thanks for the suggestions. I know a lot more about my machine as a result of exploring this problem, so learning is always a good thing.