Went fishing today and noticed the water wasnt coming out of pee hole in a steady stream while boat was at idle or when trolling. Seems like last year it came out steady no matter what. This is only the 2nd year i have had the boat and have never had the impeller replaced. Any advice would help. I do have a Manual. And would like to do repairs myself. The motor is a 1984 Mercury 90hp 2 stroke outboard.