My impeller broke apart when operated w/o muffs one day so I spent time removing the lower unit, water jacket and thermostat cleaning out all the small pieces. I have replced the impeller, thermostat and temp sensor and still can't get enough water flow. It seems ok until I am trolling for salmon at 3 mph for a couple hours, then the overheat alarm goes off. I pull in all the lines and speed up until the engine cools. I have taken it apart 3 or 4 times and I can't find anything, anywhere that is obstructing the water flow. Any suggestions besides "don't run it dry", Another lesson learned the hard way......Thanks.......
