Found!!!
After contacting Royal Purple in Porter, TX,
The best recommended oil grade for '85 Z50R: 10W40 (Less than 1 Qt).
Also, they recommended two (2x) Magnetic Drain Plug!
Cheers! :6:
What is the best recommanded oil grade for my Honda Z50R 1985.
I have think about using Royal Purple Synthetic Motorcycle 4-Cycle oil but I don't know if is 10W30, 10W40 or 20W50? :7:
Royal Purple Motorcycle Oil
Also, what is the exact recommanded quantity when empty?
Many thanks...