Haven't touched the needles? Why is that? The needles are set to run, but nothing else. Let the low needle be rich, and ASAP tune the high needle for good throttle response and non-sagging top end best power. Needle settings are only good for one altitude and/or prop-muffler combo. Factory settings cannot cover all so:::::
You should adjust the carb. Do not run prolonged full throttle, but do let the engine work hard and give it some time to cool in between. Then let it work as hard as possible again, until all is limbered up.
That should take about 10 running hours. (At ~1.5 oz fuel each minute makes 900 oz of fuel or ~6 gallons)