2008 Evinrude E-TEC 55MFE Technical Manual, Page 181Get this manual
COOLING SYSTEM THERMOSTAT SERVICING
THERMOSTAT SERVICING
Disassembly
Remove the thermostat cover and O-ring from cylinder head
HEAD" facing thermostatRefer to Cylinder Head Installation on p2011Cylinder head seal 002445
Inspection
Inspect all parts for cracks, heat damage, or signs of corrosionReplace damaged partsClean debris from housing and parts