What type of motor oil would be best for my bike. Manual says 10w-40 motorcycle oil. Would I be fine using one of the regular motor oil brands that don't use friction additives? What about diesel motor oil? More zinc and less of the crap.

On to the gear boxes. It says to use hypoid 80W in the front and hypoid 90W in the rear. Would regular 80-90w work?



My dad bought the bike with 200 miles on it in 1981. Hasn't been on the road since 1995. I plan on changing that.

 

Should be shared tranny/engine casing.

I believe in the Rotella T6 hype. But that's your call.