raceman

Hey im new here and i just picked up a 1970 Yamaha Ct1 175 from one of my buddies and it wont shift at all. The shifter wont budge one bit. I took both side covers off an noticed that the gear thats located behind the clutch basket is broken and another gear that is connected to the drive sproket has a few teeth missing out of it. Would this have anything to do with it not shifting? The engine turns over. Ive never taken apart a transmission on a motorcylce before but I am a handy man when it comes to fixing things and working on engines. If anyone has any ideas or even diagrams of how to take it aprat that would be terrific. Thanks, Jake