The Yamaha YZ125B 1991 3XJ2 NORTH AMERICA 213XJ-100E1 parts-list contains seven hundred ninety-four parts.
The FRONT FORK schematic contains the largest amount of parts with sixty-eight listed products.
To discover exactly which parts you require use the on-line schematic exploded diagram - it will even give you some idea of where and how to fit those new parts.