I'm new to I/O so I apologize for posting a topic that has already been "beat to death". But I don't know where to start. The boat is a 1981 Imperial with a "470" 170 hp, 224 ci, 4 cyl. Mercruiser. When cruising at 2800 rpm temp is at 165 but as soon as I cruise faster the temp starts to rise. I...
