Update:
Turns out, it was NOT the little fuel booster pump. (guess I've got a spare now, huh ?)
What it takes to stop my Yanmar DEAD IN IT'S TRACKS is a small wasp.
The intermittent fuel issue came back. Fuel in the tank was down to about 1/4, and driving along, it stopped dead again. I got it back to the shop, and let it run, got off, sat on a bucket behind the tractor, and REALLY watched the fuel bowl under the left fender. I could actually SEE the fuel being sucked out of the bowl, the level dropping...then it would raise some, then drop, and finally when it dropped enough (tractor at fast idle), it will kill the engine from fuel starvation.
OK....SOMETHING is in the dang tank. Took the line off.....fuel just dripped. Stuck a small screwdriver up in the tank nipple....fuel gushed....apparently I moved whatever was over the fuel outlet to one side, and fuel ran. So, I'm thinking the tank HAS to come off. PITA job....fender plastic has to be loosened and raised among other things to get the tank out they way they have it tucked in under it....couple hour job at least. So I left the tank dribbling fuel out of another hose I put on the tank outlet into a fuel can, and intended to come back in the morning to remove the tank.
BUT, I laying in bed at midnight, and thought some more....hey...I've got a Rigid brand inspection camera for looking behind walls/etc I bought not too long ago....let me try that. Jumped up out of bed at midnight (wifes says 'are you nuts ?')(40+ years, you'd think she would know, huh ?) and went to the shop. Got the camera snake in the tank, down on the fuel outlet from the inside, and sure enough, I could see "something" off to one side of the fuel hole. Couldn't tell exactly what it was, other than it looked like something with wings. The screen on the camera is only about 3" square, so it ain't exactly HD quality.
Got a set of long, flexible 'grabber' tongs I have and using the camera and the tongs, I managed to get it grasped in the tong fingers and pull it up out of the tank filler port hole. Fortunately, the tank filler hole and the fuel outlet hole are both on the same side of the tank. Out came a small, black wasp.....very small....not a stinger type, but small than them. We call them 'dirt daubber' wasps here.....they build long, mud nests and pact them full of spiders for their hatching young to feed on until they eat their way out the end of the nest. They LOVE any kind of little hole to build in....the ground hole on an electrical receptacle for example....or leave an air tool out in the shop, and you'll find they filled up the air quick connect with mud/wasp eggs..you hook air to the tool and absolutely NOTHING happens.....grrrrrrrrrrrrrrrr..... If you don't have this cursed things in your region of the world, consider yourself BLESSED.
Brought it back up to the house on a paper towel, and showed it to my wife, who was less than impressed with my discovery, to say the least....ahahahaaaaaaa....."go to bed, you old fool"....
Only way I can figure it got in the tank is it MUST have been in my fuel hose nozzle from my diesel tank, because the cap is never off the tractor tank except to fill, and the diesel tank has a 10 micron filter between the tank and the hose....so the hose nozzle is the only point I can think of....wasp must have gotten in the nozzle, died, and I flushed him and fuel into the tank when I filled it at some point. Did I mention they LOVE to check out any kind of hole for nest building ?
ONE tiny wasp folks....that's it. Nothing else in the tank. I used the camera to go all over it. Last time this happened, while under warranty and it drove the dealer nuts too, it was a couple of plastic shaving 'spirals', like from the tank molding or drilling the fuel outlet (and the return on the other side) would together along with some small trash that did the exact same thing.....floated over the fuel outlet and blocked enough fuel flow that the tractor died in the middle of running.
You'd THINK some kind of filter up in the tank you could pull out from below would be in order, huh ?
SURELY I can't be the only one this has happened to twice now ?????
I'm sure wide open for a suggestion on how to modify the tank for an in-tank filter !
I found EXACTLY what the tank needs in the form of a fitting with a screen that goes up in the tank that was used on some older model Ford tractors at the tractor dealer....but it had 3/8" or 1/2" male pipe threads that were clearly meant to go on a female pipe thread hole in the tank on that model....and I can't figure a way to use it on the Yanmar plastic tank....but it was the perfect design.....removable, cleanable filter about 1/2" in diameter x 2" long sticks up inside the tank to screen out any large crap from blocking fuel flow....GREAT IDEA....now how to put one on a plastic tank ??
Even a larger fitting on the tank (1/4" is what's on there) with a large hose to the fuel bowl would probably work....anything to let enough diameter flow/trash to allow flow TO the filter on the bowl would do the trick.
So far, I can't come up with a fix. But I'm SURE glad I bought that Rigid camera !! (had to track down a blockage in our house central vacuum line) That saved hours of tank R&R, plus I STILL might not have gotten out what the problem was !....or believed that was it, even if I had seen it flush out of the tank ! With the tank in place, and the outlet blocked right now, the wasp was sitting right next to the fuel outlet hole where I'd moved it aside with the screwdriver.....so I knew that was the problem. Kudos to a $79 Rigid camera !
