Suzuki 2002-2005 DF4/DF5/DF6 4-Stroke Outboards Service Manual, Page 33Get this manual
PERIODIC MAINTENANCE
4Measure the valve clearance by inserting thickness gauge between the valve stem end and the rocker arm09900-20803Thickness gauge Valve clearance (cold engine condition)IN 0.03 0.07 mm (0.001 0.003 in) EX 0.03 0.07 mm (0.001 0.003 in) If the valve clearance is out of the specification, adjust the clearance
1Lock nut 2Pivot nut 3Valve clearance