2006-2010 Suzuki DF150 / DF175 4-Stroke Outboards Service Manual, Page 42Get this manual
PERIODIC MAINTENANCE
6Install shimIdentification number should face down (towards tappet)7Rotate crankshaft to be open (lift up) valve8Remove tappet holder and tighten camshaft housing bolts to specified torque" Camshaft housing bolt: 12 Nm (1.2 kg-m, 8.7 lb-ft)
Special tool Tappet Camshaft