1992 Johnson Evinrude "EN" 9.9 thru 30 Service Manual, P/N 508142, Page 147Get 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 Company
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_
t=I ture must be gauged at the top of cylinder head
To achieve accurate and consistent readings, engine tempera-
For the following engine operating temperatures and RPM figures to be correct, the inlet water temperature must be 70 100 (21 C)Pyrometer Procedure 1Install correct test propeller and place engine in test tank