4 months isn't that bad, but to top it off with and add fuel stabilizer wouldnt hurt anything. I like to use Seafoam at double recommended strength, or the Marine (blue) Stabil. How many miles on oil? if high mileage, the acids and other contaminates 'could' be a problem. If under 1-2K I wouldn't worry about it. If you are worried about tire pressure, I always pressurize up to 50-60lbs when letting bikes sit to help avoid flat spots. At a minimum, I'd stabilize and top off the fuel.
I'll be deploying again in FEB/MAR (7 months) so will wait till then for fresh oil, covers, stabilized fuel, and over pressured tires for my Bikes and the 912.