2006-2010 Suzuki DF150 / DF175 4-Stroke Outboards Service Manual, Page 40Get this manual
PERIODIC MAINTENANCE
4Rotate crankshaft counterclockwise to bring cam nose vertical to shim surface5Measure tappet clearances by inserting thickness gauge between cam and shim surfaceTappet clearance (cold engine condition): IN 0.23 0.27 mm (0.009 0.011 in) EX 0.30 0.34 mm (0.012 0.013 in)09900-20803: Thickness gaugeThis is left hand (LH) rotation powerheadRotate crankshaft counterclockwise to prevent water pump impeller damageNOTE: Rotate crankshaft and measure clearance for each tappet respectively by bringing cam nose vertical to shim surface All tappet clearances can be measured during two crankshaft rotations6If out of specification, adjust tappet clearance by changing shimADJUSTMENT Tappet clearances are adjusted by replacing tappet shim1With cam nose vertical to valve, turn tappet cut-away towards center of cylinder head as shown in figure