Snakeriversailor77
Contributing Member
Im working on a 2008 Johnson 150 FICH, which is the port motor of twins. The engine runs greats, starts well, has solid compression. It was having a overheat problem at @3300 RPM under load. Replaced both thermostat/pressure release valves on each bank. Replaced the impeller. Ran a dose of Salt Away through it as well according to the instructions. The boat now still runs fine but overheats at @3800 RPM under load. The starboard engine is not overheating and runs well. What am I overlooking? Didn't find excessive corrosion or sand under the thermostats or in the water pump. The old impeller looked ok but had taken a set as most do over time. Boat is back in the water again so it is difficult to drop the lower unit again.