wrong petrol in mower?

drain it out of the tank, take off the rubber tube comming out off the bottom of the tank, or take the cap off the tank and turn it over , into a bucket, take out the spark plug and clean/dry it, or just pull the starting cord, with the engin off , to dry off the spark, refill the tank with petrol. and turn it on and try start it.it will start after a wile,

m
June 2012