1996 Johnson Evinrude "ED" 90 CV 88 thru 115 Service Manual, P/N 507126, Page 127Get this manual
Engine Temperature Check The Markal Thermomelt Stik is heat-sensitive marker that melts on contact with surface of specific temperatureOne sou rce for Thermomelt Stiks is Stevens Instrument Company
At least two Thermomelt Stiks or digital pyrometer should be used to accurately determine the engine's operating temperatures
The 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
f21 To achieve accurate and consistent readings, engine temperature must be gauged at the top of cylinder headTo troubleshoot and isolate cooling system problem properly, be sure to test both cylinder heads
r::=J For the following engine operating temperatures and RPM
figures to be correct, the inlet water temperature must be 700 100 (21 30 e)Pyrometer Procedure 1Install correct test propeller and place engine in test tank