I am replacing the thermostats and pressure relief valves as a maintenance procedure on my 150 Johnson model#J150tlcur. I noticed some crystals under the pressure relief valves; probably salt crystals since I run in both salt and fresh water. What, if anything would it hurt if I put the muffs on and started the engine to clear out anything else in the water channels ? Don't plan on racing the engine speed up; just want to make sure there is a good flow of water. Thanks for any input.
