Yea, it's a big plus not needing 2-stroke oil and having to remember to keep that tank full too, or in the case of many of mine mixing Klotz synthetic 20:1 with gas before putting it in the tank.
As you peruse these forums you'll find a hundred "What Oil" forums have already been created and many more will be upcoming so I'll get that topic out of the way.
These bikes aren't too picky about oil so long as you DO NOT USE anything that has the "Energy Saving" seal on it which is about any car oil that's got the higher number as W30 or lower. Those oils contain slippery additives that can play heck with oour wet clutches and most automotive oils are seriously lacking in the Zinc content we need to help lubricate the gears at top efficiency.
Perhaps the favorite around here is Shell Rotella 15W40, an oil designed for diesel engines and used by at least half the "over the road" semi drivers. THe trucking business is a big one and word gets around quickly thus they produce a great quality oil that still has a lot of zinc in it to help maintain their reputation. Mobil makes an equivalent called Delvac, also in a 15W40. You can usually find these oils for $10 - $12 a gallon at places like WalMart or any large store or truck stop.
The new Shell T6 5W40 Synthetic is also good, perhaps a little better if you're in a very cold climate but it costs a ton more.
Between our clutch operating in an oil bath and our gears sharing the crankcase oil there are a lot of "shear" forces involved which tend to break down oil a lot faster than normal, thus the reason for wanting an oil with a high Zinc content and the best policy being to change your oil often with the cheap stuff. Filters are still dealer items but a lot of us buy them in volume pack deals from sellers on eBay or other independant motorcycle parts vendors.
When changing the filter don't overlook the washer that goes between the spring and the filter, it often gets stuck to the filter and goes unnoticed or in many cases it's already been lost long ago. Nothing really special to it, you can get it from the dealer or some hardware stores will have something close enough. It's not an "oh no" if it's gone, it's merely there to keep the spring from digging into the filter rubber.
Change cheap, change often as in 3,000 miles or preferrably less depending on how hard you ride your bike.
The high-revving engine is normal but while it freaks out most others being used to 2-strokes that shouldn't bother you. These engines were as finely tuned as a sewing machine and paying attention to common maintenance will reward you with something that will last almost forever.
