Caution: Wear safety glasses in order to avoid eye damage.
| • | Broken teeth (1) | 
| • | Damaged teeth (2) | 
| • | Chipped teeth (3) | 
| • | Worn teeth | 
| • | Uneven wear on one edge of the teeth | 
| • | Worn valleys between the sprocket teeth | 
| • | Crankshaft sprocket keyway for wear | 
| • | Crankshaft sprocket woodruff key for wear or damage |