After sitting this winter I bought this mower and he just filled it up with fresh fuel now when I spray ether is air filer box it will only run for a few seconds?

Js 29 will not keep rinning after spraying ether in filter box

You might have to clean the carb or drain the carb bowl.something is blocking the fuel pickup in the carb.
Luck
P.S. I would never spray either in a small engine.