2000-2005 Yamaha F40B Outboard Service Manual, Page 244Get this manual
IPOWRI WJ: IEXHAUST COVER INSTALLING THE OIL FILTER
Install: Oil filter Refer to "REPLACING THE ENGINE OIL AND OIL FILTER" on page 3-12
CHECKING THE THERMOSTAT
Measure: Valve operating temperature Valve lift Out of specification Water temperature Below 60C (140 OF) Above 70C (158 OF)