Good to see.
I am a bit confused too, you can get more revs, you can get more power, you change gearing and all has to come out of a little donk. Something has to give! I am just trying to keep it efficient, smooth within reasonable expectations and hope for a bit faster without killing it .. I am taking the assumption that they are a bit restricted and underpowered within their abilities as sold to us.
I have just got a secondhand muffler of a Kwakka 250 to play with, cheap enough I can cut and weld and knock about.
Be sure to take pics at all stages, many folk would enjoy that and some would benefit from your experience, including me.