Okay, THIS looks like it could really improve these china girl motors.
BUT.
This isn't a bolt and go if you want to see real power gains that justify another hundred dollars.
To do that you'll need to cut boost ports up from the intake area, and avoid the piston ring retaining pins. To do THAT you need a good dremel tool, Carbide cutting burrs, and a REALLY GOOD idea of what you're doing. The good news is that these motors are so sloppy that chances are that it'll all work out.
I'd only reccomend this part if you've Already replaced the head with a puch head, dismantled and inspected your motor when brand new, cleaned up all the porting, balanced / trued the crank shaft, Stuffed the crank case, and you've got a nice performance pipe on the bike already.
If you haven't done these things already, the reed valves will be a waste of cash, because:
You'll realize better performance gains from the DIY stuff first, then the pipe, Then the head, then The reeds. But for absolute best performance, do them all when you get the motor.
