Farmall Cub

WE had something similar happen on a truck we had. WE had installed a saddle tank on it and it ran good. from time to time it would cut off, only to restart when the tank switch was moved.
When you switched back, it would run a while.
We finely pulled the tank and found some clown had rolled up a sheet of paper, and stuck it in the filler. It became fuel logged and floated around the bottom of the tank until it got near the pickup, and was sucked over it cutting off the fuel. When we switched tanks, the suction was broken, and it floated away.

Just when I was about to pipe in " Check for loose connection on switch ".....Glad you got it....

I had figured it was something electrical since it was so abrupt stopping. Low fuel seems to sputter then stop. Thanks again.