Small Engines (Lawn Mowers, etc.): Lawn mower, oil mixture, running order

Question
My son accidentally put a gasoline oil mix for my chainsaw in my 4 stroke push lawnmower.  Now the mower runs very rough and will not run at high speeds.  Is there anything that can be done to get this back in running order ?
Thanks..
Larry

Answer
Hi Larry,

You could just drain the fuel and replace it with fresh gas.  Run it for at least 5 minutes to clear the oil mixture out.  If that doesn't restore the engine then replace the spark plug which might be oil fouled.

Let me know how you make out.
Michael