Yes I let the old gas sit in the carb. I never had a problem before, but there is always a first time. I will drain and pour some fresh gas. I hope this works and thanks for the quick reply.It is only one spark plug. hehe.
Taking the bowl off the carburator and cleaning out the old gas sometimes works for me. You can also see if the float is working properly. Some mowers don't have a float in the carb. If you can take the carb off and spray carb cleaner in all the ports and stuff it will run a lot better. The varnish left from old gas can really gum it up. I also mix about 2 gallons of gas with a can of berryman's carb cleaner. This will really clean it out during the first few hours of operation during the season.