if that doesn't work put some atf (auto transmision fluid) in a spray bottlle and squirt it in the intake while it running, spray it in fast so that you stall it...let it sit again and start it the next day, take it for a good drive to blow it out...
Years ago my parents assisted running my grandfather's marina in New York (Star Island Yacht Club for the folks in the know). Folks always had problems after winterizing their boats poorly, where the motor would get rust inside or get gummed up from old diesel. My father would run the motor up, and pour Marvel Mystery Oil into the carb(s) until the engine died, then store it just like that. Springtime came around, change the plugs, fire it up, smokes like a bitch and is good to go. Marvel is fantastic.
Glad the OP got it figured out with the water...it's a good system. Steam cleaning.