That's the normal preformance parameters of that type motor stock, just broken in, well tuned & running properly.
It's a common misconception that shift kits aid top speed - they don't, if anything they (very) marginally reduce absolute top speed through increased friction & drag (additional chains, redirects & bearings)... provided the final ratio is the same between geared & ungeared comparison ofc.
What they do provide (at the cost of somewhat increased complexity & thus maintenance) is vastly improved acceleration & a more comfortable cruise, as you can gear it so you're not running redline at your desired speed.
The single most desirable aftermarket part for a distinct increase in preformance is nothing more than an expansion chamber exhaust - it's an intrinsic part of a two stroke engine, left out of the kits to cut costs & can be had for as little as $20 from ebay/etc (some fabrication required as those are pit bike/scooter pipes). The most important preformance modification is "port matching" - opening the intake & exhaust manifolds (grind/file) & trimming the intake & exhaust gaskets to match the intake & exhaust ports in the engine as best you're able - which is far easier than it sounds lol http://motorbicycling.com/showpost.p...1&postcount=25
from this thread: http://motorbicycling.com/showthread.php?t=16646