I came home from a long trip in October 2014 and changed the engine oil(synthetic) It has sat other than local trips to and from storage and to get maintenance. I have started it up every month or two...
You haven't changed the oil in more than a year and a half? Your short trips and just starting it every once in a while are the absolute worst thing for an engine. Oil will become acidic after a while, which is why you would change the oil on a time interval as well as by mileage. Why on earth would you risk damaging such an expensive rig for the cost of an oil change? Penny wise, pound foolish.