I purchased a boat with a 1995 Evinrude 150hp Intruder on it (serial # G 03931537) last year. I noticed this year that when I throttle down quickly from wot I can hear a slight knocking sound from the motor. I heard that this "deceleration knock" was common for Eagle series motors. So my questions are what can be done to fix this, and since it is an 11 year old motor, what damage could it have done since this problem was obviously not addressed by the previous owner? Thanks.