I have a 89 Vision Bass Boat with a 1990 Johnson 90HP motor. I went out Saturday and when I left the boat ramp, boat was running fine. We stopped in the middle of the lake to check the map, but when we started again the boat was running very slow even though it was at full throttle. The boat would not even plane. Once I turned the motor off, I also had some difficulty starting it. I had to re-prime the bulb to get it started, it has never done that before. Got the boat home, hooked up a hose and muffs, and it started perfectly. Any ideas?