Irrpcanada,
Listen to what RCKen says. He is 100% correct. I have a Nexstar, and did the break in per the O.S. manual that comes with the plane. The engine runs great. One thing I would suggest. Do a search on here for Nexstar. You will find all these threads on what you need to do to your Nexstar BEFORE you fly it. For example, remove all of the engine mounting bolts and re-install using lock-tite. Check out the threads. It will save you some headaches, and maybe your plane. Don't get me wrong, the Nexstar is a good plane and a blast to fly. It's just not quite as ready to fly as they say it is. Have Fun!!!