My Yamaha 5500 had an oil filter and still Yamaha insisted the oil and filter be changed every hundred hours. I fixed that wagon with a screw-on oil filter adapter and a base and oil filter for a Baldwin B-88. A Cummins 400 horsepower engine. But it was that little 2 cylinder Kubota engine that influenced me to buy a 6 cyl. Kubota for the KATO.
I've noticed Ultra Low Sulfur GASOLINE resists turning black as easily as non top-tier fuel. I've gotten my son-in-law to use Premium in his Yamaha 2 cycle 60 HP outboard. Now if I can find "the" better quality 2-cycle oil I will be a happy camper.
