check out the previous comments - then go fly - and listen - At this point in learning about your engine - the important thing to remember is that it needs some time to get properly seated -
Don't fret over the rpm - it will change -
you probably have heard the sound of the engine when you were peaking it -and noted that running it too lean, it sagged and the sound changed
Be prepared to land the model if it appears that it sags at all when climbing -or at anytime in the flight.