Take the starter off and give it a good clean out, compressed air and a rag to mop up the mess. Remove the plug and compressed air again and vice versa til it's all dry. Remove the fuel tank and carby and a good dry out there too. Add fresh fuel and fire it up. Run it for about half an hour(ie. mow you lawn) to ensure all water has been removed/evaporated. It'll be good to go after that.
