Toro 200s snowblower

I have 2 toro 200s blowers. One i bought 15 years ago and runs great. Thee other i bought as a fixer upper. I have kitted the carb and set the points and checked the cmpression. 75 psi, same as the one that runs good. But it doesnt have the power that my other one has. Im not new to small engines but this has me stumped. Also what does that little reed valve type thing do that is in the cylinder above the intake? Im not sure what that is and does. Thanks in advance.