1992 Johnson Evinrude "EN" 60 thru 70 Service Manual, P/N 508144, Page 132Get this manual
Thermomelt Stik Procedure 1Install correct test propeller and place engine in test tank
i propellers to avoid accidental starting of engine
'" Twist and remove the spark plug leads before changing
2Start engine and run at 3000 RPM for at least five minutesrJl 3Reduce engine speed and run engine at 900 RPM for five minutesMark the cylinder head with 1250 (52 C) and 1630 (73 C) Thermomelt Stik4At 900 RPMthe 1250 (52 C) mark should remain liquid and glossyThe 1630 (73 C) mark should remain dull and chalky If the 1250 (52 C) mark does not remain liquid and glossy, troubleshoot the cooling system for causes of over cooling If the 1630 (730 C) mark becomes liquid and glossy, troubleshoot the cooling system for causes of overheating rJl5When the engine is increased to 5000 RPM, the 1630 (73 C) mark should remain dull and chalky If the mark becomes liquid and glossy, troubleshoot the cooling system for causes of overheating&