MOPED ARMY

use vespa parts. High comp head will help with low end (make your own) pipe carb all of those things will help you make more power. If your bike is stock that fifty jet is too big. I got more pick up by switching back to the 43(stock jet) and ditching the stock air box for a couple layers of panty hose. This won't make it "fast" just better. BTW the 13/13 carb comes with a 66 jet this will also likley be to big for a non kitted bike.

panty hose- take the clamp off your stock box cut some squares of panty place the fabric over the mouth of the carb and slide the clap over it. tighten. don't leave the edges too long but don't cut them so short that you have nothing to hold on to if you want to take them off and put them on again. dig?

Hi comp head- I never see them for sale. take off your head. if there is a gasket leave it out. it might leak it might not. you can use lapping compound so that the surfaces mate properly (do a google search on valve lapping) this will explain how to use the stuff you're just applying it differently. The head can be milled down a bit maybe a millimeter? triple check before you cut any thing!!! I'm just guessing. You can have this done at a machine shop or do it your self with a file. It has got to be absolutely flat!!! If you don't feel confident, don't do it yourself.

Pipes- buy one. The science and math behind making a properly tuned exhaust is mind boggling. The sito pipe ($60) it basically a derestricted stock pipe.

"zippy's":http://www.zippymopedparts.com is a good source for stock and some performance parts.