1978 Yamaha RD400 Service and Repair Manual

Look for RD400E stamped on the 1978 machine. The factory manual that covers it is LIT-11616-RD-40, a book Yamaha wrote to span the 1976 to 1979 RD400.

Four model years under one part number means you should treat the specification tables as the important part of the volume. Where the E differs from the earlier bikes, the difference is in those tables; where it does not, you can follow the shared procedure as written.

Engine coverage runs from removal and top end through crankshaft, clutch and gearbox, with assembly torque values in place. Carburettor settings, ignition timing, Autolube pump inspection and the tune-up figures are all given. Chassis chapters deal with fork oil quantity, swingarm and wheel bearing checks, brake wear limits and chain adjustment. Wiring diagrams and a troubleshooting order for the electrical system round it off.

Confirm both the code and the part number before you order, since RD400 listings are easily mixed up.