I was drilling some holes with my 743 and it started to act like it was running out of fuel. It was would slow down and sputter, maybe it would idle, maybe it would die. It took multiple restarts to drive back to the barn.
I replace the fuel Filter... no help. One thing that I noted, after I put the new filter on, the squeeze bulb didn't do anything to fill up the new filter. (There is a glass bowl on the bottom of the filter. )
I titled up the cab to get access to the fuel tank and found two fuel lines into the tank. Tracing them, I found that one was the "return" that came off of the end of the fuel injection line/rail. The other made its way from the tank to a shut off valve, then to the squeeze bulb, then the filter, then to the pump on the side of the engine.
I pulled the two lines out of the diesel tank. They were right angle fittings that had hose on the top side (that I had just traced) and entered the tank through two rubber grommets.
When I removed the two fittings, I found that both of them were about an inch long. One of them looked to be a bare barb or nipple that looked like it never had a hose on it (the return line). It looked like a 35 or 40 year old metal fitting... old and cruddy/ corroded, but solid. The other had a tiny spring clamp around a very thin hose that went over the nipple/ barb, but broke off where the barb got larger. It would have been easy to miss the broken hose and assume that it was the same as the return line barb/ nipple.
(But then, you'd have to ask yourself: "Self, how is fuel going to get up to this barb/ nipple when the fuel level is below one inch below the top of the tank?")
I figure that the hose was cracked and allowed air to be sucked into the line. .. and when I pulled it, it broke off into the tank.
I put a new hose on the nipple/ barb and jury-rigged a way to keep it down at the bottom of the tank.
After I restarted it, it ran sporadic for a couple of minutes while it purged out the air, then started running great. I used it for about hour out so after that.
I'm just passing along the symptoms/experience and solution in case some other "old bobcat users" see these symptoms... in case it might help.
These old Kubotas are pretty good machines, they really do want to run!
- Chessie
I replace the fuel Filter... no help. One thing that I noted, after I put the new filter on, the squeeze bulb didn't do anything to fill up the new filter. (There is a glass bowl on the bottom of the filter. )
I titled up the cab to get access to the fuel tank and found two fuel lines into the tank. Tracing them, I found that one was the "return" that came off of the end of the fuel injection line/rail. The other made its way from the tank to a shut off valve, then to the squeeze bulb, then the filter, then to the pump on the side of the engine.
I pulled the two lines out of the diesel tank. They were right angle fittings that had hose on the top side (that I had just traced) and entered the tank through two rubber grommets.
When I removed the two fittings, I found that both of them were about an inch long. One of them looked to be a bare barb or nipple that looked like it never had a hose on it (the return line). It looked like a 35 or 40 year old metal fitting... old and cruddy/ corroded, but solid. The other had a tiny spring clamp around a very thin hose that went over the nipple/ barb, but broke off where the barb got larger. It would have been easy to miss the broken hose and assume that it was the same as the return line barb/ nipple.
(But then, you'd have to ask yourself: "Self, how is fuel going to get up to this barb/ nipple when the fuel level is below one inch below the top of the tank?")
I figure that the hose was cracked and allowed air to be sucked into the line. .. and when I pulled it, it broke off into the tank.
I put a new hose on the nipple/ barb and jury-rigged a way to keep it down at the bottom of the tank.
After I restarted it, it ran sporadic for a couple of minutes while it purged out the air, then started running great. I used it for about hour out so after that.
I'm just passing along the symptoms/experience and solution in case some other "old bobcat users" see these symptoms... in case it might help.
These old Kubotas are pretty good machines, they really do want to run!
- Chessie
