2007-2009 Yamaha F15/F20 Outboard Service Manual, Page 76Get this manual
Fuel system
Checking the fuel filter assembly
NOTE: To check the fuel filter element, see "Checking the fuel filter" (3-3)1Connect vacuumpressure pump gauge and meter to the fuel inlet 12Cover the fuel outlet with your finger, and then apply the specified positive pressureReplace the O-ring, fuel filter cup, or fuel filter assembly if the specified pressure cannot be maintained for at least 15 secondsS6AG4070
Pressurevacuum tester: YB-35956-A Specified positive pressure: 50 kPa (0.5 kgfcm2, 7.3 psi)