Suzuki DF200/DF225/DF250 V6 4-Stroke Outboards Service Manual, Page 42Get this manual
PERIODIC MAINTENANCE
3Rotate crankshaft counterclockwise to bring cam nose vertical to shim surface4Measure 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 rotations5If 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