I JUST FOUND AN OLD CRAFTMAN RIDING MOWER I HIT It with starting fluid and it starts right up then died and won't start unless you use starting fluid

Hi,
First, starting fluid will damage the engine. I know it works great; put it on a rag and put the rag on the intake if you must use. Carb cleaner, some brake cleaners (flammable), WD40, CRC, etc. will work as well and are safe.
All that said, you have a filthy carb. Ought to kind of be a "no-brainer!" Why? Old mower, does crank when fuel is introduced and does not run beyond that. Tells me the carb is not doing its job.
Peace,
Clarke