Bingo! Mowed for 4 hours without a hiccup. Now for an autopsy on the old fuel tank to see exactly what the problem was.
JD ZTR Surge and die
- Thread starter kajnjim
- Start date
For anyone that’s curious, the results of the autopsy are in. Cut bottom of tank out. Floating in the unremovable fuel that was left in the tank was a piece of leaf about 3/8 X 5/8 inches. Just the right size to get sucked up against and block the 1/4” ID fuel line inside the tank. So after 3 months of swapping umpteen engine parts and stumping the entire service department at JD and myself, the mystery is solved. Guess I’ll epoxy the fuel tank back together after cleaning and I’ll have a spare that I’ll likely never need. Can bet your sweet a$$ all fuel will now go through strainer funnel.
. Thanks all. Jim
bertsmobile1
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Weld the tank
Epoxy will fail when you least expect it to
BBQed mower leaves a bad taste in your mouth
Those creamy looking milk bottles are HDPE the same material as the fuel tank
So it is clean the plastic, V out the joint just the same as stick welding and weld the seam.
File smooth than put a patch plate over the top with a hot air gun
Lots of reasonable videos about plastic welding on line just ignore the comments about using old zip ties for everything.
You must use the same plastic filler as the parent metal otherwise it will look good then fall out when the tanks gets hot.
Epoxy will fail when you least expect it to
BBQed mower leaves a bad taste in your mouth
Those creamy looking milk bottles are HDPE the same material as the fuel tank
So it is clean the plastic, V out the joint just the same as stick welding and weld the seam.
File smooth than put a patch plate over the top with a hot air gun
Lots of reasonable videos about plastic welding on line just ignore the comments about using old zip ties for everything.
You must use the same plastic filler as the parent metal otherwise it will look good then fall out when the tanks gets hot.
We have a 2010 JD Z425 with the L44 twin B&S 23 hp engine and it did the same thing the third year we had it. Just out of the blue it would start surging and die like it was out of fuel. It did have plenty of fuel. Wouldn't start back up. Let it sit 20 min. or so and tapped the carburetor and it started right up. Did this several times during that season and a couple of times the next season. Has never done it again since. I believe it was a hang up of the carburetor float for some odd reason. Never disassembled the carb or anything else but it has never done it again.
Well that brought back an awesome memory. My first JD ZTR was a Z425. My wife (who does 90% of the mowing) came to me one day and said it died and wouldn’t start back up so I turned it over and heard the most God awful noise from the engine. Removed engine and as soon as I got in it, I saw pieces of pistons and rods and cam shaft all over the place. I found an engine for $80 (pretty sure it was to fund the dudes meth habit) and put it on that Z425. Only problem was it had a different orientation than the original, so in order to get the cables connected to the carb, the engine had to be mounted 90° from how the original was. Was able to get everything connected except the muffler. I still have it as an emergency use mower, but can only use it if I wear earplugs. My wife wouldn’t think of using it. The neighbors really enjoy it.
. It’s actually my second back up. I also have a Z355E that my wife does use as her backup. Which she did often during this saga. 
Bettsmobile,
Followed your advice and did my first ever plastic welding on that tank. It was kinda fun and came out excellent. Can’t even tell it was cut into if you stand far enough away.. Thanks for the tip. 
Jim
Followed your advice and did my first ever plastic welding on that tank. It was kinda fun and came out excellent. Can’t even tell it was cut into if you stand far enough away.
. Thanks for the tip. Jim
bertsmobile1
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Glad it worked for you.
Provided you did not over heat and drive the plasticisers out so it is brittle it will be as good as new .
Provided you did not over heat and drive the plasticisers out so it is brittle it will be as good as new .
Well…bad news. Thought I had it solved, but yesterday when the wife was mowing it started again. Just on a whim, I swapped the gas cap with the 355E thinking maybe a tank vent problem, but of course that did nothing. I’m kinda leaning toward a governor problem, but not being a small engine mechanic, I’m not familiar enough with what other components and their settings/adjustments/relationship to the governor would affect the way the governor affects the way the engine runs other than the speed of the camshaft. Or am I barking up the wrong tree. Should I be looking somewhere else. Kinda lost.
You said your wife does most of the mowing. Congrats on that. Anywhoo, I was wondering is she a petite gal at 92lbs or a healthy girl? Wondering if she is lifting out of the seat causing the seat switch to open up killing the coil/s? Hitting bumps......
Next thought was check all safety switches and wiring. Clean/polish all connections and goop some dielectric grease where possible. Play around with the switch plungers and a multi-meter. Barely push in numerous times then give it the full gundy several times. Go to the next switch. Could be a bad wire too. Old mower, might be time to rewire all the switches.
Next thought was check all safety switches and wiring. Clean/polish all connections and goop some dielectric grease where possible. Play around with the switch plungers and a multi-meter. Barely push in numerous times then give it the full gundy several times. Go to the next switch. Could be a bad wire too. Old mower, might be time to rewire all the switches.