I've read that it's best to store the bike with a full tank, as that leaves less atmosphere and surface area for the fuel to pull water out of the air (for ethanol mixes).
Put another way, it leaves less room for oxidation (rust) to form on the inside of the tank which could plug everything up, once it gets vibrated loose. That's not just for an ethanol mix, that's for gasoline in general.
Oxidation cannot form where gasoline is present, unless it's broken down with time.
Using a fuel stabilizer helps keep the fuel from breaking down over time and moisture from forming inside the tank.
A combination of the two, plus cranking the vehicle once in a while works pretty well. Firing up the motor moves the fuel and stabilizer through the system, helping to fight corrosion everywhere.
Short of a "dramatic incident" nothing is more detrimental to a gasoline engine than to just be left alone for a long time.
It goes further than that, though. If the bike is on the side-stand for a long while, the tires will develop flat spots. Obviously the battery is an issue as well.
So the solution is put the bike on stands, with a full tank of gas with fuel stabilizer, and use a battery tender? Not so fast.
There's all those rubber seals everywhere on the bike. The front fork seals are what come to mind. Not to mention dry rot on the tires. Not to mention simple corrosion of electrical contacts.
Why does all this come to mind? My brother who currently lives in China recently visited the U.S. and bought a motorcycle. Said motorcycle is currently stored in the barn. I once tried to bring a poorly stored bike back from the dead. It didn't go well.
I've also personal experience with what happens to a vehicle that isn't properly prepared for and tended to during storage. When I was stationed in S. Korea, I left a great car with my parents. It was parked and forgotten. What I came back to was junk. It was DOA.
Granted, that was a year and half. Even so, there's so much involved in a functioning motor vehicle. It needs to be taken care of, and it needs to be exercised.
I ride year round. If I didn't? Full tank of fuel with stabilizer, battery tender and front and rear paddock stands. Then, when I could, I'd crank her up, roll her around and bounce up and down all the while. The idea being to work the lubrication back into the seals and the fuel through the system.
So much is dependent upon environment. Some people can just put the bike away for the Winter and then crank it up and ride way come Spring. Other's are not so lucky.
There are just too many variables. Recently my bike had to sit for weeks. I had it on stands. I cranked it up, then I moved it around, I held the idle up to charge the battery.
I didn't feel it would be sitting long enough to need fuel stabilizer, but I put in anyway. I did everything I could to the bike to make it seem as though I was riding her every day.
When I was again able to ride? Heck yeah, cranked right up and nothing the worse for wear.
Long post and word wall, but it's our bike we're talking about. If she's going to take care of you, you've got to take care of her.
