I was cruising, 1st time out of the garage, my Force 120 was running great, decided to go one last lap around the lake, taking it easy on her, all of a sudden she went dead going 40 mph, thought maybe I had moss on the prop or I hit something, neither was true, started her up, she was running rough and would not idle. I pulled plugs, all were dry. I did not hear any knocking either, just ran rough back to the dock. What do you think guys??? Help!