Rag,
The "Exercise the Generator" is a left over from WWII when the windings were sealed with a lacquer (old technology) and perpetuated but the people that sell parts and service....
You don't say what the generator is, but there has to be a way to shut the fuel to it off. You want to do this so the carburetor ends up as dry as possible. Many have a way to drain the float bowl. This may not be in the manual (Gee - Why Not?) but if you go by any small engine shop, they may well know a good way to do this.
Then, if you are not sure when you will get back to using, Fog it. This means that you crank the engine (while it is still warm is best) and spray this oil in the air intake so it coats all that bare metal that makes up the internal parts.
Now, when you want it to run again, get a battery, get fuel into the carburetor by cranking it in short bursts, and it will start. when it does, it will blow out some smoke for the first few minutes.
I have been taking care of other peoples engines for nearly 60 years. Some were miniature like this, some were small like the one in your coach and some were real and rated in 100s of horsepower per cylinder.
Matt
Matt & Mary Colie
A sailor, his bride and their black dogs (one dear dog is waiting for us at the bridge) going to see some dry places that have Geocaches in a coach made the year we married.