Yamaha TX500 & TX500A Service Manual, 1973–1975 (P/N LIT 11613-71-01)

This Yamaha factory service manual (P/N LIT 11613-71-01) covers the 1973 TX500 and 1974 TX500A. The first edition appeared in July 1973 and was revised in May 1974. This is the June 1975 third printing.

Printed Contents and Wiring Legibility

Search and navigation: Use the printed contents and page numbers to find sections. The PDF has no text search or embedded bookmarks. Small wire color codes and switch labels in the U.S. wiring diagram are readable when zoomed in.

The ZIP contains one printable PDF with 186 pages, including two front-matter pages and the 13-page parts and service bulletin section.

Engine Overhaul, Chassis Service, and Electrical Tests

These selected workshop topics are part of a manual that also includes periodic maintenance and lubrication charts.

• Engine repair: Engine removal and installation, cylinder-head service, cam-chain cutting and riveting, and camshaft timing.

• Balancer and lubrication: Omni-phase balancer weight indexing and chain tension adjustment, plus oil strainer and pump service.

• Clutch and transmission: Crankcase separation, gear and shift-fork inspection, wet clutch assembly, and kick-start mechanism service.

• Fuel system: Twin Keihin CV32 carburetor disassembly, float-level adjustment, and vacuum-gauge synchronization.

• Chassis and brakes: Front-fork and swing-arm service, front hydraulic disc-brake overhaul and bleeding, and rear drum-brake inspection.

• Electrical diagnosis: Brushless AC generator tests, starter-motor service, breaker-point ignition timing, and IC voltage-regulator testing.

Yamaha wrote the manual for its authorized dealers and their qualified mechanics, assuming familiarity with basic mechanical procedures.

DOHC Valvetrain and Wet-Sump Lubrication

The top-end sections cover camshaft journal and rocker-arm shaft inspection, valve-guide replacement, valve-seat reconditioning, and piston and cylinder measurement. The Valve Timing diagram shows how valve events differ between cylinders. Removing the camshafts in the wrong timing position can let valve-spring force turn the shafts and damage the shafts, caps, or retaining studs.

The Oil Delivery Schematic traces the oil supply to the filter, crankshaft, and camshafts. The lubrication section also covers the oil release valve and the shared pump and tachometer drive.

Crankshaft Bearings, Clutch, and Service Tools

The crankshaft section ties bearing insert selection to housing and journal size codes and shows how Plastigage is used to check oil clearance. Yamaha also refers readers to the separate TX750 Service Manual for bearing insert selection.

The Route of Power Flow from the Starter Motor illustration explains the one-way roller starter clutch. The wet-clutch section shows how to index the eccentric plates and check friction-plate wear and plate warpage.

Torque data covers M8, M10, and M12 engine mounting bolts and other component fasteners. The manual also lists wear limits and fluid capacities. Special-tool references include cam-chain cutter and riveter 90890-01112 and clutch holding tool 90890-01069.

Service Bulletins and Parts Changes

Service News 320 identifies TX500 engines that need a special initial valve setting during the transition to pressed-in seats. Bulletin M4-019 specifies a matched four-gear set when retrofitting the revised second- and fifth-gear components. Service News 382 distinguishes the early left-hand-thread rear hub from the later right-hand-thread design. The hub and its matching retainer hardware interchange as an assembly. These distinctions help you identify which parts to order together.

Other bulletins cover camshaft-case oil leaks, cylinder-head retorquing, and revised valve guides and seals. A full parts listing is in the separate model-specific parts book.

Carburetor Tuning, Chassis Checks, and Electrical Faults

The carburetor bulletin gives main-jet options for altitude and an alternate needle for midrange surging. Chassis checks cover rear shock damping, wheel bearings, spoke tension, and rim runout. Mineral oil can swell hydraulic brake seals, and Yamaha specifies new front caliper bridge bolts whenever the originals are removed.

The Operation Circuit of IC Voltage Regulator accompanies bench and on-bike checks. The Wiring Diagram (U.S.A.) maps electrical connections, and the Cable Routing Diagrams show harness, control-cable, and brake-hose routing. Troubleshooting charts organize checks by symptoms such as hard starting, poor idle, weak midrange or high-speed operation, overheating, and blue exhaust smoke.

Clutch Spring and Generator Test Examples

The clutch inspection lists a standard spring free length of 42.8 mm and a replacement threshold of 1 mm or more below standard.

At 20°C, the TX500 AC generator inspection specifies 4.04 Ω ±10% across the field coil and 0.7 Ω ±10% between each pair of stator terminals.