Sorry for bringing this back to life, but I personally bought one of these reed valves and would like to share my experience.
Firstly, they are an intake restriction as a bolt on. Expect to lose alot of power if you just bolt it on.
Secondly, your power up top increases if you window the piston. The reeds are too stiff for lower than 3000 rpm. Puts your power band way over the 6000 rpm limit
Thirdly, if you change the reeds to a different material, they will either melt or will flutter at higher rpm. Fine below 25 mph on stock 44t sprocket, anything 30+ and the engine dies.
Fourthly, one reed will hit the top of the intake.
Find a DIO reed valve with better flow. there are a few for $30 but are harder to install and another bolt on for about $50. This RSE is a waste of time as a bolt on