Check out Allen Millyard .. guy is a genius with motorbikes.
https://www.youtube.com/user/millyardviper/videos
Last one I saw was a water-cooled, 4-cylinder, 2-stroke H1 Kawasaki 500 (for those who don't know, the H1 was built as an air-cooled, 3-cylinder)
.. or if you like them big, 2.3L V12 Kawasaki, derived from Z1300 Kawasaki 6-cylinder bike ..