I have a yamaha 100hp four stroke. It was never winterized at the end off last year. It wouldn't start up the beggining of this year. I figured it was old gas in the carbs and they needed to be cleaned. I cleaned them and Reyes to start it again. The engine now gives a hickup when you try and start it but it still won't start. I cleaned the carbs again but it made no difference.

The engine worked fine when I turned it off at the end of last summer it just won't start now. I still feel like it could be old gas but suggestions.