Did I already say that it's just a 50cc, and there's not much hope of increasing speed by more than a couple of knots with a tail-wind. Kymco is no help in de-restricting your moped. Changing rollers and contra springs won't make a bit of difference, except you will now be short about $50. Changing the main jet will cost you about $6 including postage, and won't make a stick of improvement. Cutting the wire on the CDI will add about 1000 rpm, or 5mph, and that's just about all you're going to get. To get any speed out of a 4-stroke moped, you have to increase the displacement and change the gears. The cost is about $350 at a shop, and you'll get 45mph (75km/hr). Now it'll go like a bat of of hell - but it's no longer a "moped" :-)
It does 45mph now... well 50 actually (indicated - probably not that fast in reality)
thats with the lighter rollers, stock contra, CDI cut so that it now revs properly, and main jet had been changed previously. Restricted it's 30mph flat out, so that's like a 50% gain already, and yes, probably would be hard to squeeze much more out of a 50cc motor.
Might go down the road of a BBK if I get a cheap chinese project scooter to tinker with, but I'm leaving the Kymco pretty standard tbh.