1997 "EU" Johnson Evinrude 5 thru 15 Four Stroke Service Manual, P/N 507262, Page 126Get this manual
Engine Temperature CheckAll Models The Markal Thermomelt Stik is heat sensitive marker that melts on contact with surface of specific temperatureOne source for Thermomelt Stiks is Stevens Instrument CompanyAt least two Thermomelt Stiks or digital pyrometer should be used to determine the engine's operating temperatures
1For the following engine operating temperatures and RPM figures to be correct, the inlet water temperature must be 70 100 (21 30 e)2Install correct test propeller and place engine in test tank
To avoid accidental starting of engine while changing propellers, twist and remove all spark plug leads
3Start engine and run at 3000 RPM for at least five minutesPyrometer Procedure 1Reduce engine speed to 800 to 900 RPMAt 800 to 900 RPM, digital pyrometer should indicate 1400 150 (600 90 e) when held on cylinder head If engine temperature is not within this range, troubleshoot cooling system to determine problem