I have a '99 Kawasaki 1500 Drifter with 27,000 miles on it. I changed oil in it a year ago last October and have put less than 4,000 miles on the oil change (Amsoil 10W40 MC oil and Amsoil's best oil filter). Amsoil says to change at one year no matter what the mileage. I get my oil and filters at dealer's cost but will have to order more if I change the oil. We are very short on money now due to my wife's illness and I'm debating whether an annual change is necessary. The oil in the bike still looks very good in the sight glass on the case. I would send some to an oil lab but can't afford that right now, either. The bike still shifts as smoothly as when the oil was new and I have added about 6 oz. of oil since the change. What does the group think about this?