I change oil and filter on my 93 dyna lowrider before storage in extreme heat of Phoenix summer, as I'm gone all summer. When I bring lowrider alive in the fall, I change oil again. Is that necessary, or is it overkill?

 

I'm not sure what your thinking would be behind what you're doing and why you're doing it.

 

Why would you change out fresh oil that has not been used just because it sat for a few months? You're way overthinking this.

 

Overkill doing it after storage if you've changed it before you put it up for storage. Any moisture will boil off riding.
Changing your fluids before storage is the best thing you can do, you get the used oil out with acidic contaminants. Run it for a couple minutes to circulate it all around to coat everything.

 

probably an over-kill but does not hurt anything, i over-killed the maintenance on my 74ch but still going 175k later.

 

How do you know if the new oil you put in in the fall, hasn't been sitting around longer then the oil your changing out?.,,,

 

If my RK oil has less than 2000 miles use I leave it in all winter. Hasn't hurt yet in 65,000 miles. Same with my wife's Dyna and she has 110,000 miles on it.

 

By looking at the bottle. There is a date code, and, of course, the SAE rating. If that is the same, it wont matter anyhow. Oils seldom differ in formulations before a new SAE change comes around, and oil does not "age" and "go bad" just because it's sitting in a crankcase VS a bottle. There is absolutely NO reason to drain the "storage oil". To do so, is simply nothing more than a waste of resources, and another dry start.