Honda Outboard Motor BF15A Owner's Manual page 42

4. Remove the clamps used to close the fuel tubes. Connect the fuel tank
line to the motor. Turn the fuel tank vent knob to the ON position, pump
the primer bulb, and check for leaks.
NOTE:
If loss of power or hard starting is found to be caused by excessive
water or sediment accumulated in the fuel filter, inspect the fuel tank.
Clean the fuel tank if necessary.
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