Those are the same numbers I was getting. It has slowly goten better as I continue to run it. Remember there are alot of things that contribute to engine power. High altitude, humidity, temperature, and exhaust can all affect it. On a good day I have goten just under 7000 rpm on a xoar 22-8. My engine was a pain to start originally also but as I continued to fly it, the engine really got better. It takes about 4-5 flips on on the cholk and less when trying to start.