Tractor Repair: Ford 555D Tractor (Backhoe), manual shutdown, lubrication properties

Question
I was using the tractor and it was running fine.

I shut it down and the next day when I started it would not idle. (It seamed to run fine above an idle so I used it about an hour)

When I got finished that day I changed the fuel filter and cleaned the glass bowl out. I then worked for about 30 hours trying to get it started again.

My neighbor came over to help me and was looking at the tractor and he moved the manual shutdown lever on the fuel pump and it started (it has a electric shut down and we have never used the manual shutdown for the 8 years we have had the tractor. There is not even a cable hooked up to it just a spring to keep it in the run position)

Now when it is running and starts to die if we flip the manual shutdown lever it will get fuel again and stay running.
It could stay running for 10 sec. or it could stay running until we shut the key off.

So if it starts to die all we need to do is move the manual shutdown off and back on fast and it runs great until we shut it down or it starts to die again and we flip the manual shutdown level again?????????????

Help I am losing my mind.....What little is still there

Answer
The quality of fuel that we use now days does not have the lubrication properties that it used to. So the shut off rack inside the pump is probably hanging up. If you feel lucky you can buy  the socket to take off the top of the pump and see if you can free it up. Otherwise take to a shop and have them look at it.