What did I do wrong?

   / What did I do wrong? #1  

JPRambo

Platinum Member
Joined
May 14, 2012
Messages
745
Location
Dahlonega, Georgia
Tractor
kubota Bx23S, b6100
Last week I visited my property north of Atlanta. I have a shed therewith shovel and hand tools and a very used 1978 Kubota 7100 in the shed. It was very late on Friday when I arrived. The next morning I tried to start my tractor and it acted as if the battery was dead. I pulled my truck to the doorway and used jumper cables to start the tractor. It acted the same way. I gave it about a half hour to charge the battery and it still acted the same way. I checked and cleaned the battery connections and the starter connections. I just keep turning the key and after a dozen or so turns of the key the tractor started. I removed the cables and I noticed oil draining onto the rags I keep under the tractor to catch any drips ( I sometime sleep in the shed on quick weekend trips). I quickly shut off the tractor. Cleaned up the mess and looked for the reason (holes in the block or such). Nothing till I pulled the dip stick and more oil found the way to the floor. I drained the oil (should be just over 4 quarts). I drained about 1 and a half gallon not including what I mopped up from the floor. It smelled a lot like the fuel that should have been in the tank. What went wrong?????
I replaced the oil and a filter and it ran good all week. When I left on Monday I made sure the fuel tank was close to empty.
 
   / What did I do wrong? #2  
I'm not familiar with a 7100. Is that a gasoline engine? It sounds like fuel somehow drained into the crankcase. This usually doesn't happen with a diesel, only with a carbureted gasoline engine with a stuck carburetor float. The starting problem may have been because one or more cylinders was partially filled with leaked fuel causing very high compression. I'll leave it to others more knowledgeable to comment on how diesel might have leaked into the cylinders or crankcase.

- Jay
 
   / What did I do wrong? #3  
My old John Deere H had the same problem with the carb float sticking and gas was overflowing into the oil.:ashamed:
 
   / What did I do wrong?
  • Thread Starter
#5  
Yes, it is a diesel engine.
 
   / What did I do wrong? #6  
I think that the only way that diesel can get into the crankcase is through a failed diaphragm on an engine driven fuel pump. That would be the lift pump that delivers fuel to the injector pump. I suppose the injector pump could leak around the drive shaft, but that should make it run rough or miss on one cylinder as it would be getting irregular fuel supply to the cylinders.
 
   / What did I do wrong? #7  
Last week I visited my property north of Atlanta. I have a shed therewith shovel and hand tools and a very used 1978 Kubota 7100 in the shed. It was very late on Friday when I arrived. The next morning I tried to start my tractor and it acted as if the battery was dead. I pulled my truck to the doorway and used jumper cables to start the tractor. It acted the same way. I gave it about a half hour to charge the battery and it still acted the same way. I checked and cleaned the battery connections and the starter connections. I just keep turning the key and after a dozen or so turns of the key the tractor started. I removed the cables and I noticed oil draining onto the rags I keep under the tractor to catch any drips ( I sometime sleep in the shed on quick weekend trips). I quickly shut off the tractor. Cleaned up the mess and looked for the reason (holes in the block or such). Nothing till I pulled the dip stick and more oil found the way to the floor. I drained the oil (should be just over 4 quarts). I drained about 1 and a half gallon not including what I mopped up from the floor. It smelled a lot like the fuel that should have been in the tank. What went wrong?????
I replaced the oil and a filter and it ran good all week. When I left on Monday I made sure the fuel tank was close to empty.

Any chance someone tampered with it? If it sits unattended, that could be someone's idea of a neat prank. Reason that comes to mind is I just had to work on a lawn mower my 12 year-old grandson innocently put gasoline into the crankcase. Thankfully he used old gas that had degraded badly, so it didn't explode. Have to say, it sure cleaned out the crankcase and there seems to be no permanent damage. Unlike a lawnmower, it would be hard to mistake the fuel cap from the oil cap on your tractor, of course, but someone with mischief in mind...
 
 
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