1998–2000 Yamaha WR400F(K) Owner's Service Manual PDF (P/N 5BF-28199-80)

The 1998–2000 Yamaha WR400F(K) Owner's Service Manual, publication 5BF-28199-80, is the first edition dated December 1997. It covers operation, inspection, tuning and mechanical repair for the regional 5BF configurations.

• Engine and transmission: Engine removal, crankcase separation, camshaft timing, valve service, piston inspection, clutch repair and internal gearbox checks.

• Carburetor and ignition: KEIHIN FCR 39H disassembly, throttle-position sensor inspection and adjustment, CDI magneto service and ignition fault tracing.

• Cooling and lubrication: Radiator-cap testing, cooling-system inspection, water-pump shaft and seal service, and oil-pump inspection.

• Brakes and wheels: Master-cylinder and caliper disassembly, brake bleeding, disc inspection, wheel-bearing replacement and steering-bearing service.

• Suspension and swingarm: Front-fork service, linkage-bearing replacement, swingarm side-clearance adjustment, and rear-shock spring and mounting-bearing work.

• Tuning: Carburetor setting charts, optional jets and needles, sprocket selection, suspension settings and symptom-based adjustment charts.

• Workshop illustrations: Electrical Components and Wiring Diagram, Cable Routing Diagram, Lubrication Diagrams, exploded assemblies, job instruction charts and sectional views.

Owners can use the operating and routine-maintenance sections; the internal repair material is suited to mechanics familiar with engine disassembly and the specified special tools.

Maintenance and Internal Engine Repair

Maintenance schedules organize pre-ride, race-based and mileage-based inspections. The starting and break-in material has gaps at printed pages 1-13 and 1-15; routine-service pages 3-9 and 3-11 are also missing.

Engine work extends to valve-guide replacement, valve-seat lapping and valve-lifter shim selection. Crankshaft removal and installation use dedicated tools, including crankcase separating tool YU-01135-A / 90890-01135.

The camshaft section warns that uneven cap tightening can damage the cylinder head, caps and camshafts. Clutch inspection covers friction plates, plate warpage and spring wear; the kick-axle and shift-shaft material has a gap at printed page 4-60.

Carburetor Settings and Electrical Diagnosis

Float-height measurement and TPS resistance checks accompany the carburetor assembly instructions. Tuning charts relate throttle opening, atmospheric conditions and running symptoms to jet and needle selection. Text on printed carburetor page 4-12 is cropped in the English and German versions.

The map-controlled CDI explanation links throttle-position and engine-speed signals to ignition timing. The Ignition System flowchart helps narrow a no-spark fault to the relevant switches, coils, connections or TPS before the CDI unit is condemned. A separate Lighting System flowchart covers the lamps, switch, lighting coil and regulator.

Water Pump and Oil Circuit

Water-pump coverage identifies the impeller shaft, oil seals and right crankcase cover, with inspection and installation notes. Oil-pump procedures include rotor-clearance checks, while lubrication diagrams show the delivery paths through the engine and transmission.

Fork, Linkage and Brake Service

Brake procedures cover piston and seal inspection, master-cylinder assembly and bleeding. Swingarm service includes linkage bearings, bushes and side-clearance shims.

Front-fork disassembly and inspection are documented, but printed assembly and installation pages 5-35 and 5-39 are missing. A specific assembly caution explains how a dropped damper rod can damage the internal valve; Yamaha recommends dealer servicing for this assembly.

Rear-shock work covers removal, spring replacement and mounting-bearing service. The handling instructions explicitly prohibit opening the pressurized nitrogen cylinder or reservoir; this is not an internal damper-rebuild procedure.

Examples of Valve-Train, Drive and Cooling Data

These figures are a small selection of the manual's inspection limits and assembly specifications.

Cold valve clearances are 0.15–0.20 mm intake and 0.25–0.30 mm exhaust. The camshaft runout limit is 0.03 mm; the torque table lists 10 Nm for camshaft caps and 7 Nm for M6 x 1.0 cylinder-head studs.

Drive data specify a 62/21 (2.952) primary reduction. Cooling-system capacity, including all routes, is 1.15 L.

PDF Bookmarks, Language Coverage and Page Count

Search, navigation and diagram detail: PDF text search is unavailable. Embedded bookmarks cover all seven chapters, although the Clutch entry opens partway through that section. Small wiring labels require zooming. English specification pages 2-3 and 2-4 are missing; their French and German counterparts are included.

One printable 578-page PDF contains English, French and German text: 25 pages of front matter, 545 chapter pages, five memo pages, two blank pages and one back cover. All are included in the total.