1990 Johnson Evinrude "ES" Cross V 88 thru 115, 150 thru 175, P/N 507874, Page 157Get this manual
JIi III III
IT] Thermostat ServiceV6
Removal There is thermostat and pressure release valve in each cylinder headService each thermostat as follows: '21 1Loosen but do not remove the four thermostat cover screwsTap the cover lightly to break the gasket sealerCarefully remove the four cover screws, the cover, and the pressure release valve spring r;] 2Remove and inspect the thermostat
and the pressure release valve Also inspect the pressure release valve spring that was removed with the coversure release valve seat
Gil f51 f6l 3Remove the cylinder head cover to inspect the pres and washer Cleaning and Inspection 1Thoroughly clean the cover and cylinder head gasket surfaces to remove traces of sealer and gasket material2Clean and inspect pressure release valve, spring, and thermostatReplace any damaged componentInstallation