Great job. People tilt the model vertically to check for a sagging engine. Any engine sag lets you know there's an over lean condition. Slowly lean the engine until the RPMs pick up a bit more. Make sure the engine transitions from idle to full well. Run the engine at idle for 20 seconds and then briskly move the throttle to full (don't snap it). Chances are the engine will either sputter and die or sputter and pick up eventually. This would mean that you need to lean the low end a little and try again. Do this until your transition is good.

In short, the engine will be rich, but reliable when ready to fly.