1994 Johnson/Evinrude "ER" 60 thru 70 outboards Service Manual, Page 142Get 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 RPM, the 1250 (52 C) mark should remain liquid and glossyThe 1630 (73 C) mark should remain dull and chalky