1997 Johnson Evinrude "EU" 125C, 130, 200, 225, 250 90 LV Service Manual, P/N 507269, Page 195Get this manual
Engine Temperature Check 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 accurately determine the engine's operating temperaturesThe Thermomelt Stik mark will appear dull and chalky when the surface marked is below the Stik's rated temperatureWhen the surface exceeds the Stik's rated temperature, the mark will appear liquid and glossy
rn To achievegauged atand consistent readings, engine temperaccurate ature must be the top of each thermostat pocketTo troubleshoot and isolate cooling system problem properly, be sure to test both cylinder heads
INote For the following engine operating temperatures and RPM
figures to be correct, the inlet water temperature must be 70 10 (21 C)Pyrometer Procedure
Twist and remove spark plug leads before changing propellers to avoid accidental starting of engine1Install correct test propeller and place engine in test tank2Start engine and run at 3000 RPM for at least five minutes