I just bought a boat with a 2000 50 hp Mercury 3 cyl. 2 stroke. It seems to run very well at all speeds but idle. It wont idle below 1000 rpm for very long and it changes idle rpm speeds erratically. Sometimes it will have a miss and will die (at low rpm's only). Also I ran it yesterday and tach suddenly stopped working. This is my first Mercury . Just got my repair manual today. All advise appreciated Thanks, Richard