Originally Posted by markkris

In general (myself included) the majority of people who buy a rtr are relativly new to rc or at least new to nitro. the factory needle settings that the mfg provide are usually on the safe side. to us inexperienced people if its fast and trouble free most of the time we think our tune is good. but if you meet someone with years of experience with theese engines the difference is huge.
it takes time to learn to tune correctly, if possible try to find someone to give you a hand. a proper tune will extend engine life and make your rc time more enjoyable.
good luck... Mark