From The Boulder Street Moto Garage...our very own Randy Troy master mechanic advice and knowledge...
I know, everyone and their mother has an opinion on the best motor oil. Truth is, most people overthink it when the answer is pretty simple: pick the stuff that has been working well on these vintage engines from the very beginning. I've been running Honda GN4 10W-40 in all of my bikes and it works great. Some folks like to alternate between 10W-40 in winter and 20W-50 in the summer. Stay away from synthetics and always change your oil every 1,000 miles. For real...every 1,000 miles.
