I can get my flywheel to my 78' 75hp evinrude spinning, but she doesnt want to turn over. I checked all 3 spark plugs for failure, but they are all sparking, and the killswitch isnt engaged, so im not really sure where the issue is. Maybe wiring or gunky carbs?

The motor looks to be in great shape, but it hasnt run in maybe a year or so. A friend of mine tried some starting fluid to get it going and it rolled over once. I read online now that starter fluid is terrible for 2 stroke outboards. Will this single application have any negative effect on the motor?

oh, and the fuel is a couple years old. I didnt have  chance to change it yet. Its a fix-er-up boat. Maybe the fuel?

-Thanks in advance

Do a search and read the post on fuel. That will answer most of your questions.

One shot of fluid will not hurt the 2 stroke.

I would not use starting fluid.  Use a spray bottle with premixed gas, just like you run in the motor.  Give each carb a pretty good shot and keep spraying it each carb when it does start.  If it runs doing this, you have a fuel problem.  The three barrel carbs on those motors are a little tricky to rebuild, and will cost you approx $200 to have them done, just be sure you use someone that knows how to do them.  I've had to redo a number of them that others considered themselves rebuilding.   You can also get a kit for the fuel pump, it's pretty easy to do.  

I hope you did get rid of any gas that was left in it from sitting that long.