Yamaha YZ250A and YZ250WRA 1990 Owner's Service Manual (P/N LIT-11626-07-06, LIT-11626-07-12)

• Four Yamaha factory publications, 582 PDF pages total: YZ250A Disassembly and Reassembly Edition, P/N LIT-11626-07-06 (45 pages); YZ250WRA Disassembly and Reassembly Edition, P/N LIT-11626-07-12 (155 pages); YZ125A/YZ250A/YZ250WRA Operation, Inspection, Adjustment and Tuning Edition, P/N LIT-11626-07-14 (120 pages); and YZ250B Owner’s Service Manual, P/N LIT-11626-07-56 (262 pages).
• Engine repair coverage includes carburetor and reed-valve removal and installation, cylinder and piston work, YPVS power-valve service, clutch and primary-drive repair, kick and shift mechanisms, CDI magneto service, engine removal, crankcase and crankshaft work, transmission assembly, and radiator/water-pump service.
• Chassis procedures cover wheel and bearing work, front and rear hydraulic brake disassembly and bleeding, fork teardown and seal installation, steering-head service, swingarm and relay-arm work, and rear-shock spring removal and installation.
• Inspection and tuning sections address cooling-system checks, clutch and throttle adjustments, carburetor inspection and jetting, drive-chain and steering setup, ignition-timing checks, gearing choices, suspension setup, improper-setting troubleshooting, and setting-record tables.
• Electrical references include component-location and wiring diagrams, a no-spark inspection sequence, spark-gap testing, engine-stop switch checks, ignition-coil and CDI-magneto resistance tests, and CDI-unit fault isolation.
• YZ250WRA correction material supersedes original ignition-timing, torque, and cable-routing information in LIT-11626-07-12 and LIT-11626-07-14, including revised clutch-cable, high-tension-lead, and CDI-magneto-lead routing.
• Special-tool data identifies the crankcase separator YU-01135, crankshaft installer YU-90050/YU-90062, rotor holder YU-01235 and puller YM-01189, clutch holder YM-91042, piston-pin puller YU-01304, fork-seal driver YM-1424, and damper-rod holder YM-1423.

How the Set Is Organized

This is a four-publication factory set, not one 85-page manual. The July 1989 YZ250A and YZ250WRA material separates disassembly/reassembly from operation, inspection, adjustment, and tuning; Yamaha directs the reader to use those editions together when service data or adjustment procedures are needed. The June 1990 YZ250B book combines specifications, maintenance, teardown, electrical diagnosis, and tuning in one volume. Yamaha’s own warranty text limits owner-performed service to qualified mechanics and recommends dealer handling where special tools or equipment are required, making this set best suited to experienced owners and technicians equipped for precision two-stroke and chassis work.

Model and Serial Identification

Coverage is tied to Yamaha model codes and starting numbers. The shared operation/tuning volume identifies the YZ250A by the 3SP series, starting with VIN JYA3SPW0*LA010101 and engine number 3SP-010101; the YZ250WRA is model code 3RB2, starting with VIN JYA3RBW0*LA005101 and engine number 3RB-005101. It also contains YZ125A/3SR data. The YZ250B manual distinguishes 3XK1 for Europe, 3XK2 for the USA, Canada, and other markets, and 3XK4 for Australia and New Zealand, with region-specific VIN, frame, and engine starting numbers.

One important limit affects repair planning: the supplied LIT-11626-07-06 PDF is a 45-page partial file. It ends at carburetor installation page 3-6 even though its contents list later engine and chassis chapters. It should not be treated as a complete YZ250A bottom-end or chassis teardown file. The WRA and YZ250B publications do continue through their full engine and chassis sections.

Repair Data, Diagrams, and Tuning Depth

The specification sections provide component torque data and tightening patterns, fluid capacities, approved lubricants, wear limits, running clearances, piston/cylinder classification, clutch inspection limits, crankshaft checks, sprocket and suspension setting parts, and electrical test values. The procedures pair those references with removal, inspection, reassembly, and final adjustment information instead of stopping at routine maintenance.

Useful visual references include the corrected cable-routing diagram, electrical-component location views, color-coded ignition wiring diagrams, the ignition-system inspection flowchart, exploded front-fork and brake assemblies, and front/rear suspension symptom-and-remedy charts. The tuning material connects plug readings and riding conditions to jetting changes, compares gearing options, explains fork and shock setting effects, and supplies blank setup records.

Corrections and Shop Cautions

For the YZ250WRA, the correction insert changes the ignition setting to 1.1 mm BTDC (0.043 in), shown as 13° at 8,500 rpm, and replaces affected torque and routing data. This corrected sheet matters when the original LIT-11626-07-12 or LIT-11626-07-14 values are still visible.

The repair notes warn that uneven reed-valve screw tightening can warp the assembly. During fork teardown, bottoming the inner tube while separating the tubes can damage the oil-lock piece, while letting the damper-rod assembly fall into a vertically held inner tube can damage its valve assembly.

Brake hydraulics, gasoline, engine work, and pressurized suspension components require appropriate tools and safety procedures. The manual reserves rear-shock gas-release disposal for Yamaha dealers; follow the factory warnings and use qualified help where the repair exceeds your equipment or experience.