@blue : cutting the boss down and using a thinner belt have the opposite effect, you're sure that's exactly what you meant to do at the same time ?
Most tuning parts for all mopeds and scoot that I owned in my life turned out to be of an inferior quality compared to the original parts.
My current aim is to use as little tuning parts as possible, only change the parts that really make a large difference and ignore all possibilities which don't add much power but involve using non-kymco parts or modifying Kymco parts...
I once fitted a sh**ty Malossi Torquedrive which rattled and leaked grease all over the place and didn't make enough difference to justify the annoyances, I tried cutting the CDI which made the engine run very rough but did not add the kick I was hoping for, and I have tried lots of small modifications to things like intake manifold and exhaust without noticable effect...
Tinkering and playing around can be fun but I will stick with the things that are proven to make a real difference (at least I guess I will...
) My Agility now only has a 72cc big bore kit, a NCY T2 camshaft and a NCY Overdrive 2 variator and I'm quite happy with it.