1990 Johnson Evinrude "ES" Cross V 88 thru 115, 150 thru 175, P/N 507874, Page 150Get 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 Companyleast 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 glossy6469
t=J ature must be gauged at the top of cylinder head
To achieve accurate and consistent readings, engine temper-
To troubleshoot and isolate cooling system problem properly, be sure to test both cylinder headsFor the following engine operating temperatures and RPM figures to be correctthe inlet water temperature must be 70 100 (21 C)Pyrometer Procedure 1Install correct test propeller and place engine in test tank