2003 johnson 70 hp overheating

[tkdstycrk]

I have a 4 stroke 70 hp Johnson that overheats at high RPM's. it will idle and run up to 3000 rpm's without any problems. when I run it up to higher . RPM's it over heats. I have changed the water pump and thermostat and flushed the engine out with a salt away product. Does anyone have any other ideas how to correct this problem?

 

[daselbee]

there is a poppet valve below the thermostat. look lower on the side of the engine, there is a smaller hose running right next to the thermo hose that goes on the poppet housing. those poppet valves stick sometimes. two bolts takes the housing off, poppet is underneath. need a gasket too.....

 

[tkdstycrk]

thanks I will try changing that and see what happens.