B. G. ,
You need to use 10W-40 and it needs to be a motorcycle oil. Really doesn't matter what brand, just not for a Harley since it's basically automotive oil. What you're dealing with is 2 wet clutches, the transmission, and roller bearings. Automotive oil is not designed for these applications. Motorcycle oil has the additives needed to address these issues. I'm sure you'll get other opinions. I've been in the business almost 25 years. Just my . 02.
Scott