Yamaha Outboard F15A F9.9C, FT9.9D F15 Service Manual, Page 136Get this manual
INSP ADJ
POWER UNIT
4Check: Valve clearance (With feeler gauge 1) Out of specification AdjustValve clearance Intake: 0.20 0.05 mm (0.008 0.002 in) Exhaust: 0.25 0.05 mm (0.010 0.002 in)