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What I do....
Before storage I put in new cheap dyno oil and a new filter
I also give it a healthy shot of Fogging oil
Spring take I good ride then drain it and put in
MObil 1 4xt motorcycle oil stays till next fall.
I can only parrot that supposedly old oil has acidic combustion by-products that can corrode internal surfaces. Especially in storage where moisture accumulation will remain until motor is hot again.