Hey, boat,
Fellow NexSTAR flyer, here. A couple hints...


Sounds to me like the engine has not been broken in, yet.

1. Take the limiter off of the high end needle. Start at the recommended settings and take your time. Small adjustments after a short pause. Let the engine catch up to the adjustment.
2. Use a tach. It's better than trying to listen to the changes.

As mentioned before, you can turn this motor over the compression. But, it will feel a little tighter after break-in.

Good luck,

Have a safe flight day,
E J