1995 Johnson Evinrude "EO" 90 CV 85 thru 115 Service Manual, P/N 503150, Page 128Get this manual
Thermomelt Stik Procedure 1Install correct test propeller and place engine in test tank
i and remove all spark plug leads
'" To avoid accidental starting of engine while servicing, twist
2Start engine and run at 3000 RPM for at least five minutesf41 3Reduce engine speed and run engine at 900 RPM for five minutesMark both cylinder heads with 1250 (52 C) and 1630 (730 C) Thermomelt Stik4At 900 RPM, the 1250 (52 C) marks should remain liquid and glossyThe 1630 (73 C) marks should remain dull and chalky If the 1250 (52 C) marks do not remain liquid and glossy, troubleshoot the cooling system for causes of overcooling If the 1630 (730 C) marks become liquid and glossy, troubleshoot the cooling system for causes of overheatingf41 5When the engine speed is increased to 5000 RPM, both 1630 (730 C) marks should remain dull and chalky If the marks become liquid and glossy, troubleshoot the cooling system for causes of overheating