Asked this same question in the past with the manual stating to "Store for long term" blah, blah......
You know what I ended up doing was just to start it up and let it heat up for a few minutes and move it out into the drive way then back in the garage. I did it about every 2 to 4 weeks. Probably not necessary after all but made me feel better.
For me its only a mild Florida winter all of about 3 months. I just like to keep things running and not to sit too long.:smile: