I have a small engine inverter generator. This generator is to be used during power outages which happen rarely where I live, and also tested shortly every 2 years (the testing is also to keep the electrolytic capacitors in the inverter healthy, as a non-used electrolytic capacitor can degrade).
The user's manual says these about storing the generator:
- It should have no fuel inside the tank or carburetor (which I do by letting it starve of fuel, and there's also a fuel drain tube with screw in the carburetor)
- I should remove spark plug, put a tablespoon of oil into the cylinder and, slowly pull the recoil cord to lubricate the cylinder with ignition off to prevent electric shocks from the loose spark plug wire, and reinstall the spark plug
I will also be doing this, which this generator's manual does not have but many other brands of generators to have this in the manual:
- I change the oil before storage (which I obviously do since this is the single most important maintenance of an engine)
- I pull the recoil starter until I feel little bit of resistance (which should ensure the valves are closed)
The main problem I'm having is that the spark plug access cover is way too small. It seems very awkward to even remove the spark plug wire, not to mention fully removing the spark plug. Perhaps the generator was designed by someone with really small hands. So I thought that I might want to skip this step.
How harmful is it if I don't put oil in spark plug hole of a stored engine?
I can imagine at least two problems that might occur:
- If the generator is stored outdoors, humidity could condense inside the cylinder and cause rust, destroying the engine. However, I won't be storing the engine outdoors, I store it indoors in a heated space, and besides, if I ensure the engine is stopped with valves closed (by pulling the recoil cord until I feel resistance), that should also make it harder for water to condense inside the engine. So rust shouldn't be an issue.
- When starting the engine, a layer of oil in the cylinder walls could help avoid wear. However, if I expect the generator to work for 30 years, I will have maybe only 15 starts without oiled cylinder walls. Can 15 such starts really damage an engine?
What is the primary reason for the advice about oiling the cylinder walls? Is it to prevent rust, or is it to ensure good lubrication when the engine is started after long storage?
The engine has splash lubrication (no oil pump, no oil filter).