2003 Johnson ST 6/8 HP 4 Stroke Outboards Service Manual, PN 5005471, Page 101Get this manual
FUEL SYSTEM
CARBURETOR
Test Procedure
Do this test with the motor in test tank or on the boatBefore testing, loosen fuel tank gas cap momentarily to release any pressure that may have built upFuel tank must not be more than 30 in(76 cm) below fuel pumpRemove carburetor to fuel pump hoseConnect fuel pressure gauge between the carburetor and fuel pump
CARBURETOR
Removal
WARNING
Do not attempt to run engine with any fuel system component disconnected or removedFuel leakage could contribute to fire or explosionRemove the manual starterRefer to MANUAL STARTER sectionRemove hoses from air horn and carburetor fuel and water nipplesRemove air horn screws and air hornIf necessary for clearance, remove oil pressure sender wire from sender