That's perfect for starting out. Get used to tuning it, pay attention to how it performs when tuned right and how it sounds. When it starts acting differently, pay attention to what it is doing. Listen to the RPM's, is it bogging or cutting out, etc. and make your adjustments. As you are more confident with how well you can "read" what the engine is telling you, then you can decide if you want to stick with 20% or go higher.