2009-2010 Suzuki DF70A DF80A DF90A Outboard Service Manual, Page 146Get this manual
1D-35 Power Unit Mechanical: 6) Hold valve spring compressed with special tool and install valve cotters (6)Make sure valve cotters are properly seated in groove "A"NOTE When compressing the valve spring, be careful not to damage the tappet holeSpecial tool (C): 0991619030 (Valve lifter) (D): 0991614521 (Valve lifter attachment) (E): 0991684511 (Tweezers)
Cylinder Head Components Inspection and Servicing
Z9J0111406018
If cracks, excessive wear or other damage is found on any component, replace componentCylinder Head Remove all carbon from combustion chambersNOTE Do not use any sharp edged tool to scrape carbon off cylinder head or its components Be careful not to scuff or nick metal surfaces when decarbonizing