h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

please be aware. "leaning" (not un-fattening) your carb's will cause your combustion chamber to run much hotter. this will soon melt your piston. this is bad. i wouldn't recomend anyone without proper knowledge of combustion theorys to mess with the main jets ( or nossels ). as for point 5, race pistons are lighter to allow an engine to rev' higher safely, but will not cause an engine to rev higher. my advice would be to consult someone with lots of experiance.
ex-twostroke racer and tuner

Tampering with inlet and exhaust ports should not be advised to an amateur either. A tiny bit cut off, in the wrong place, could not only make the machine unridable, but also impossible to start.

Ditto, the cutting of piston skirts. Uncovering transfer ports at the wrong time could be disasterous.

Leave the two stroke tuning to the experts.

By far, the best way to make a moped go faster, is to fling it off a cliff!!!!!

you obiously know what your talking about why r u an ex stinkwheel tuner. i have a dt 50 and rd 250 and it is bloody hard to find two stroke tuners