There could be several reasons for this, the most common being:

1. Rich mixture
2. Oil injector pump out of adjustment
3. Dirty air filter element

It's common to see a little oil on the tips of the pipes, but usually means it's time for a service!

If the bike never really made it to full operating temperature, this can cause oil residue to form in the chambers too.

Has the bike been stood for a long time? Have there been any modifications since it was last ridden?

Andy.
NSR-WORLD.COM