Unlike all other machines the Honda 450R has the engine oil seperate from the transmission, so you can run a slick JASO MB oil in the engine (but NOT the transmission!). I have been running Honda HP4M (with moly) a JASO MB oil, but am looking for alternatives. I like Maxima Ultra, because it is a Group V Ester Synthetic, but it is a JASO MA (not as slick as a JASO MB). The only JASO MB syntheric I have found is Amsoil Group IV PAO Series 2000 Synthetic 20W-50 Racing Oil.

Lots of reading if you would like to educate yourself about oils:

http://www.thumperfaq.com/oil.htm

http://www.maximausa.com/technical/l...beNews2002.pdf

http://motorcycleinfo.calsci.com/Oils1.html#Oil