I don't have the .45, but I've got 2 of its baby brother, the 3.5cc. One is on my Shrike 10, and it works great. The other is still in a box waiting for me to figure out what to put it in. I would expect the RPM range to be similar to K&B's .45 marine engines, up to about 25,000. The only bad thing I've found about my 3.5 is that it makes many of my other planes seem too tame!
