Lx172 Runs Well for 29 minutes then stop!

   / Lx172 Runs Well for 29 minutes then stop! #1  

GBM

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Tractor
Lx172
Hi,

My 1993 John Deere LX172 ran great and then all of a sudden stopped after about 20 minutes and wouldn’t run until it cooled off. I’ve cleaned the fuel tank, replaced everything from the tube in the gas tank to the carburetor including tube in tank, tubing, valve, filter, pump, and carburetor. Also filter and changed the oil. Next I replaced the coil and the firing order chip. After all this still runs for about 29 minutes and then stops. One thing that happens as it starts to stop is I get gas from the carburetor thru the short tube releasing gas onto the frame of the tractor.
I’ve had a repair shop look at it and they tightened the carburetor which I had replaced and replaced the fuel filter just because they felt that was the fix.
No fix as it still does the same thing, and ideas of what I can do next?
Gary Morgan
 
   / Lx172 Runs Well for 29 minutes then stop! #2  
Does it stop like you turned the switch off, or does it start slobbering or missing and die.
Does it have spark after it dies?
 
   / Lx172 Runs Well for 29 minutes then stop! #3  
Disconnect the fuel line just before the carburetor. Make sure you have good fuel flow there. It's possible you've shaken something loose in the tank which is partially blocking flow but allowing enough flow to refill your lines and refill the carburetor as the tractor sits. It's also possible your new fuel filter is defective. As a test you could try running with no fuel filter in place. Is the float in your carburetor sticking, preventing or slowing fuel flow into the carburetor. Is the needle valve sliding freely or sticking in any way? By all means, exhaust the dumb stuff before getting into the expensive things.
 
   / Lx172 Runs Well for 29 minutes then stop!
  • Thread Starter
#4  
Does it stop like you turned the switch off, or does it start slobbering or missing and die.
Does it have spark after it dies?
It starts slobbering and dies, no backfiring at all.
 
   / Lx172 Runs Well for 29 minutes then stop!
  • Thread Starter
#5  
It starts slobbering and dies, no backfiring at all.
 
   / Lx172 Runs Well for 29 minutes then stop!
  • Thread Starter
#6  
Disconnect the fuel line just before the carburetor. Make sure you have good fuel flow there. It's possible you've shaken something loose in the tank which is partially blocking flow but allowing enough flow to refill your lines and refill the carburetor as the tractor sits. It's also possible your new fuel filter is defective. As a test you could try running with no fuel filter in place. Is the float in your carburetor sticking, preventing or slowing fuel flow into the carburetor. Is the needle valve sliding freely or sticking in any way? By all means, exhaust the dumb stuff before getting into the expensive things.
 
   / Lx172 Runs Well for 29 minutes then stop!
  • Thread Starter
#7  
I’ve tried all of this with a new carburetor, as that what I though was the issue, fuel flow but I’m getting good flow to the carburetor and in fact when this happens I get fuel from the carburetor drain line flowing out of the carburetor onto the tractor frame which is dangerous on a hot engine.
 
   / Lx172 Runs Well for 29 minutes then stop! #8  
So your carburetor starts to overflow and it dies? Sounds like you've found your answer. I'm guessing that carb didn't come out of a Kawasaki box.
 
   / Lx172 Runs Well for 29 minutes then stop!
  • Thread Starter
#9  
Actually your correct but the original factory carburetor that I replaced did the same thing. To me it seems like the carb is working but it stops getting pulled into the manifold or just maybe my spare plug wire i bad when it gets hot??
 
   / Lx172 Runs Well for 29 minutes then stop! #10  
The problem with these knock off carbs is that they turn into tail chasers. The carb won't overflow if it is working properly. Maybe you can lower the float level in the carb and keep the vent in a position to where it doesn't turn into a siphon. Is there another vent in the venturi that is blocked?
 
 
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