Honda EU10i Owner's Manual page 41

3. Turn the fuel cap vent lever fully counterclockwise to the OFF
position.
Be sure the fuel cap vent lever and the engine switch are OFF when
stopping, transporting and/or storing the generator.
4. When parallel operation has been executed, pull the special cable
for parallel operation.
38
FUEL CAP VENT LEVER
SPECIAL CABLE FOR PARALLEL OPERATION
(SOLD SEPARATERY)
OFF
OFF