1983 Yamaha 30EN Outboards Service Manual, Page 32Get this manual
Fuel joints are fitted to both ends of the fuel hoseThe fuel joint on the TAN MA side of the fuel hose is connected to the joint on the fuel meter housing on the fuel tank, and the other joint is connected to the joint on the bottom cowlingWhen either one of the fuel joints is connected to the mating joint, the steel ball in the fuel joint is pushed in, and thus the valve either on the fuel tank or the engine side is opened Removal
WARNING:
Gasoline is highly inflammable and explosiveAvoid smoking while servicing the fuel systemAlso, keep away open flames and sparks1Fuel meter assembly Remove the four screws, and pull the fuel meter assembly out of the fuel tank
When connecting the fuel joint to the fuel tank, be sure to loosen the air vent screw in the fuel tank capIf not, fuel may spout out of the joint on the fuel tank side