1992 Johnson Evinrude "EN" 40 thru 55 Service Manual, P/N 508143, Page 147Get this manual

1992 Johnson Evinrude "EN" 40 thru 55 Service Manual, P/N 508143, Page 147

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

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 surfac,e 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 headFor the following engine operating temperatures and RPM figures to be correct, the inlet water temperature must be 100 (21 30 C)

Pyrometer Procedure