2005 Yamaha F90TR 90HP Outboards Factory Service Manual, Page 50Get this manual
Fuel system 6Apply the specified positive pressure and check that there is no air leakageDisassemble the fuel pump if necessary
Checking the fuel pump
1Place drain pan under the fuel hose connections, and then disconnect the fuel hoses from the fuel pump2Connect the special service tool to the fuel pump inlet3Cover the fuel pump outlet with finger, and then apply the specified positive pressureCheck that there is no air leakage
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NOTE: Assemble the fuel pump valve to the fuel pump body, and moisten the inside of the fuel pump with gasoline to ensure good sealSpecified pressure: 50 kPa (0.5 kgfcm2, 7.3 psi)