QuestionPaul, I have a JD F525 with a 17 HP Kawasaki. My problem started three years ago. The mower would die for no reason while mowing. Give it full choke and it would start right up and keep on mowing for another hour or so...no big deal. Fast forward to today. The problem has gotten steadily worse over time. Today's symptoms are the mower will start fine, back out of the shop, get into the grass and starts dying pretty quickly now, less than a minute. I have found out that I can keep it running if I give it full choke. It actually runs enough to keep mowing, the power is cut in half though. After 15-30 seconds, the mower starts losing all power and I can quickly move the throttle back to the fast position and can mow under normal power for another minute or so. Here's what I have tried so far. I have replaced the air filter, 3 spark plugs of different power ratings, fuel filter and blown out the fuel line from the tank to the carb. I have disassembled the carb and found no trash. I'm not sure what a rebuild would consist of on these. It looked pretty simple to me but I am NO expert on these! I took out the main jet under the float of the carb, no trash, used an entire can of cleaner on it and reassembled. No change. I took it to my JD dealer last winter and explained the symptoms. The mechanic installed another filter and spark plug and tested. It ran fine for two mowing then started back again. I tried another plug and filter but no change this time. After pondering this for a while, it occurred to me that the mower was blown off during transport so I get the air hose out and blow it off again. It seemed to improve some but not for long. This evening I noticed the fuel pump was caked with debris so I concentrated air on the little screen on the pump until it was clean. It ran somewhat better for 15 minutes then nothing again. My fuel filter is clear. As I watch the fuel being pumped, the flow is on and off. I assume the pump only pumps when the float in the carb drops but I'm not sure. What am I missing? is it the fuel pump, do I need a professional carb rebuild, or is it electrical, coil, ignitor? I have even heard it could be valves. I think valve problems would come on faster. I don't mind buying parts for it but I am trying to avoid buying everything. Where should I start? These symptoms happen mainly while mowing but I have gotten it to do it with the PTO wires unplugged, under a heavy load by climbing a hill at full throttle. Thanks, Jim
AnswerI pity you Jim. A F525 is the worst thing to work on ever built.
First off, it's not the fuel pump!
The fuel filter always looks empty, it's an air density/vacuum/suction thing.
I have 2 very strong ideas about what's going on. Unfortunately I said 2 not 1.
My first thought would be a clogged pick up tube in the tank. The tube in the tank gets packed shut from the fuel pump suction. When you shut the tractor off it eventually loses its compaction and fuel will run again.
If you are sure the carb is clean check this first. It's free!
But, it sure sounds like a bad ignitor to me.
