It is important to test your generator every few weeks. “Why? I don’t want to do that every few weeks!”
I’ll tell you why.
A gasoline engine can be very unforgiving if you let it sit around for a long time between uses. They like to be used. It is their purpose in life. It is fun for them.
I have a number of low use gasoline engines that like to give me a hard time if I don’t exercise them occasionally. The problem is almost always caused by the gasoline becoming old. Gasoline that becomes old settles, gums up and leaves deposits in the carburetor float valve and jets.
Stuck Float needle valve
If your engine won’t start then it is possibly a stuck needle valve. After sitting a long time the valve will often become stuck in the cylinder and will not move to allow gasoline to enter the carburetor. You will have to remove the float bowl, remove the float pin and the float and needle valve being VERY careful not to break the needle or lose the tiny spring. Clean the needle well and replace everything in reverse order.
If the jets get clogged then there may be gas in the carb but it is not getting into the engine. You will have to remove the jet with a screwdriver and clean the hole with a tiny wire before reinstalling it. You might as well check the jet if you are cleaning the float needle valve since you are already inside the carb.
After reassembling it will probably start right away. Carburetors are basically pretty simple. If they are clean, they work.
To prevent having to do this when you have a power outage, it is best to put a tiny bit of gas in the tank and run the generator until it is all used up every few weeks. This way you are using fresh gas that will clean the valve and will not be sitting there in the carburetor causing it to gum up.
There are additives you can put in the gasoline like Sta-Bil but I am dubious about whether they really work or not. You can try them if you like.
When the EMP comes or the wild hurricane or tornado comes through you don’t want to have to be taking the carburetor apart to clean it. Just to a maintenance run every two weeks and both you and your generator will be much happier.