I would never recommend starting fluid on a 2 cycle. I would be concerned it would create a lean condition - not enough lubricant to the Engine. if you need to prime it use 2 cycle mix.
I wonder if the pickup tubes in the tank could be plugged with rust or other crap.
IMO you need to do a flow test on the fuel pump per the manual.
Be careful - guys have blown up engines not knowing it was not getting proper fuel flow.
Engine rebuild is expensive.
Take your time and you will figure it out. Post a picture or two please.
Remember you are dealing with a 35 year old machine.
I'm waiting for CO to Chime in. He is the fl350 pro.
a lot of info here - please read up and get a manual.