Yamaha EF2200iS Owner's Manual page 56

Storage
6-3
1.
Remove the spark plug, pour about one table-
spoon of engine oil (See page 5-3) into the spark
plug hole and install and tighten the spark plug to
the specified torque. Recoil start the engine by
turning over several times (with ignition off) to coat
the cylinder walls with oil.
2.
Pull the recoil starter until you feel compression.
Then stop pulling. (This prevents the cylinder and
valves from rusting).
3.
Clean exterior of the generator and apply a rust
inhibitor.
4. Store the generator in a dry, well-ventilated place,
with the cover placed over it.
5. The generator must remain in a vertical position
when stored, carried or operated.