Honda BF50 (5HP) BF5A Outboard Motors Shop Manual., Page 41Get this manual
BF5OeEF5A
6CYLINDER HEADIVALVE
aDISASSEMBLYREASEMBLY
1 CYLINDER HEAD [I] INTAKE VALVEIEXHAUST VALVE
REASSEMBLY: Check the valve head for carbon deposits or pitting before installationDo not interchange the intake and exhaust valves, VALVE HEAD DIAMETER: Intake: 25 mm (0.98 in) Exhaust: 24 mm (0.94 in)
REASSEMBLY: the carbon deposits from the combustion chamber, Check the valve seat contact before installationMeasure the cylinder compression after installation
[2] CYLINDER HEAD GASKET