Yamaha Outboard F15A F9.9C, FT9.9D F15 Service Manual, Page 142Get this manual
INSP ADJ
LOWER UNITGENERAL
Lower unit leakage check 1Check: Pressure Pressure drops Inspect the oil seals and componentsChecking steps: Connect the leakage tester to the oil level checking holeLeakage tester: YB-0359590890-06762 Apply the specified pressurePressure: 100 kPa (1.0 kgcm2, 14.2 psi) Check that the lower unit holes the specified pressure for ten secondsNOTE: Do not overpressurerize the lower unitExcessive pressure may cause the air to leak outTrim tab check (for S-transom model) 1Inspect: Trim tab Damagecracksbends Replace