I forgot that my Toro 4 cycle weed whacker takes regular gas. I accidentally, put gas in the whacker mixed with oil. The engine started with no problems however after about 5 minutes it started to run roughly and when I tried to press on the level to turn the whacker it stalls. After realizing what I had done, I changed the gas. Now the whacker runs, however, it stalls every time I press on the lever to get the whacker working. My question to you is: Can I clean the engine out and have I messed up the engine completely?
Thanks for your help.

Remove the plug.
Spray carb cleaner in the plug hole.
Put rag over hole.
Crank until you get the muck out.
Put in new plug.

Start. Spray the air horn.

BtW: Carb cleaner can be used as starting fluid. Never use starting fluid in a small engine.