Mercury Mariner 4, 5 102CC Sail 1990 Outboard Service Shop Manual, Page 170Get this manual
11 Connect fuel hose to fuel pump and secure with clip OPERATING INSTRUCTIONS IMPORTANT: The outboard may be operated by either using the integral fuel tank or remote fuel tank but should not be operated usi ng both tanks at the sa me timeOperating Outboard Using Remote Fuel Tank
Failure to close fuel cock will allow primer bulb to squeeze fuel into the integral fuel tank or fuel system may draw fuel from both tanks at the same time resulting in the introduction of air into the fuel lines If one tank is emptyIMPORTANT: When remote fuel line is attached to fuel connector, 360 degree steering of outboard cannot be used1Tu rn fut ;e lecto lever towards rear outboa rd (closed position) Fuel Pump