1992 Johnson Evinrude "EN" 90 deg. Cross V Service Manual, P/N 508145, Page 162Get this manual
Thermostat Service4
INotel The thermostats and the pressure valves should be serviced when the powerhead is removed from the adapterRemoval The thermostats and the pressure valves are attached to the exhaust housing adapterService as follows: 1Remove cover screwsTap thermostat cover lightly to break gasket sealer and remove cover2Remove gaskets, thermostats, grommets, springs, and pressure valvesDiscard gaskets and grommetsCleaning and Inspection 1Thoroughly clean the cover and adapter gasket surfaces to remove traces of sealer and gasket material2Clean and inspect pressure valves, springs, and thermostatsReplace any damaged component