GAGAK, that's a VQ Zero. It weighs 7 lbs. 1.8 oz. I asked Dave Shadel in the YS Engines Support Forum about the high RPM, and he said it was fine. In fact, he said that you'll encounter problems if you run the YS 63 too slow. Here is the link to the thread:

http://www.rcuniverse.com/showthread...52&forumid=156

My YS 63 peaks out at around 11,500 rpm..