Honda Outboards BF40A/BF50A Service Manual, Page 411Get this manual
BF40A-BF50A SPOOL VALVE, SLEEVE, VALVE B
Check the sliding surface of the valve S, spool valvesleeve for damage, scratches and wearReplace if necessary[1] SLEEVE
[2J SPOOL VALVE
(3) VALVE (2)
-2-WAY VALVE
Check the 2-way valve for damage, scratches and wearReplace if necessary
"OIL TANK