Need advice

[Wired Wrong]

I have a friend ( the only one)ha-ha he has a 2001 Ranger witha 200hp Mercury. he bought the boat 3 years ago we took it out and ran it all is well. He didn't crank it until today after it sat all this time,He said it started fine but when he nailed it it gurgled and skipped and shut down and would not start again.
I am guessing that the old gas has gummed up the injectors.Can anyone tell me how to help this old boy out.Thanks