Lawnmower won't start after tipping?

Remove spark plug. Spray some brake cleaner or carb cleaner into sparkplug hole. Pull rope a few times. Spray some more in sparkplug hole. Pull rope a few times. Remove airfilter and check for oil in air filter. If you tipped it up so carb was below engine, oil gets in carb. Spray carb cleaner into carb. Clean and install filter. Pull rope a few more times. Clean plug and reinstall. It should start. It'll smoke for a bit, but it'll burn off.