What are you looking for? Power or speed? Smaller pitch numbers give you more RPM and more power, but lower speeds.

But, just remember that noise does not relate to speed nor power. The RPM numbers that show up on spec sheets for various engines are not really useful nor practical. The RPM range you are working with is probably where I would keep it at for good practical flying. If you want more power, go to a bigger engine.

Tune the engine so that it is below peak RPM so that it is slightly rich. If you are not sure how to tune the engine at full throttle, ask. We will be glad to 'walk' you through this.

CGr.