1981 Yamaha YZ125 Service and Repair Manual

Model code YZ125H belongs to the 1981 YZ125, and the factory book for it is part number LIT-11626-02-60. Coverage is that season alone.

Race machinery is rebuilt often, which makes the inspection chapters the part of the manual that sees the most use. They tell you what to measure and give the limit at which each component should be replaced, so decisions about a tired top end or a marginal clutch are made on figures rather than on how the parts look. Torque values, ignition timing, carburettor settings, suspension specifications and the wiring diagram fill out the rest.

Because Yamaha revised the YZ125 annually and gave each year its own part number, confirm YZ125H on the frame label before ordering. A manual from the year either side will look similar and specify different numbers.