on a serious note I've always used full synthetic mobile 1 with mobile 1 filter in my cars and all the bikes I've owned and the busa I currently own. you will get a million diff. answeres.. in the end you will have to decide how much you want to spend and which oil you feel comfortable using. GL.
Well I gotta say that I am only using "Conventional" Oil for my busa and not straying from it, hey it's a steet bike and if it were a track bike that I worked on constantly then I would use Royal Purple.
Why conventional, because it is all about the clutch folks, since the transmission and engine all use the same lube, the clutch is the weakest link in a sense. A good example is if you bought new clutch plates you are supposed to soak them in conventional petroleum oil overnight; However if you soak them synthetic, you can just throw them away - they are now ruined. Synthetic is too slippery for the clutch and if you do go with it, expect to replace your clutch plates every 10,000 miles or so. Stick with conventional oil and your plates will last and last.
A good dyno tuned bike with the right parts and good riding skills will more than make up for any gains you get from a synthetic. My dealership mechanic also suggested sticking with synthetic, he's been working on bikes his whole life.
Oh and replace your oil & filter every 2,000 miles - period!!
Oh but one more thing, if you are already using synthetic, I would say go ahead and stick with it. Now that the bike has synthetic I would dump conventional in the case now, doesn't mix well and could gum up. On your next engine rebuild, ya know when you bore it over to a 1500 and get a blue printed crank and extensive head work , start over with conventional.
I use Royal Purple in both my bikes. 02' Turbo and 09' n/a. Speaking of the clutch plates, what about a lock-up clutch like many of us have on our Turbo Bikes?? My lock-up has seen Royal Purple for 14,000 miles and the plates are beautiful. I know people that burn the hell out of their clutch with regular oil and only get 5000 miles out of them. It depends on the clutch you have and how you ride also.
Well good points and perhaps so. If you slip the clutch like I do on launch- ya know to keep the RPM's high while leaving the line, I may have to replace them every 10k anyway but won't know until I check then.
Hey I guess it may not really matter but one thang is for certain, put some kind of damn oil in it. My friend that runs a motorcycle performance shop has had a few customer that brought their bikes in because of an engine seizure. Turns out they were about out of oil and black and syrupiee. yikes, hello get a clue.....