I use mobile 1 20-50 motorcycle oil. I know that I should use a thinner oil as this oil was really designed for an air cooled bike. But I've read where systhatic 20-50 actually runs thinner than dino 20-50. I also use k&n oil filtures. I know the reason it is such a free flowing filture is because it can let large bolders thru it's filture material but what to heck it works great with that thick oil I'm using. I also change the oil every 4,000 miles weather I need it or not. I'm probably spending too much on oil and filtures but what the heck; it makes me feel good. Isn't that what motocycling is all about.