Yamaha YZ426F Owner’s Service Manual Set, 2000–2002 (P/N 5JG-28199-80)

These are separate model-year editions. Use the manual and market specifications matching your machine: service data and adjustment methods change between editions, including the TPS setting procedure.

Rear shock scope: Coverage includes removal, spring and bearing service, and external adjustment. The nitrogen-pressurized damper cylinder and reservoir must not be disassembled; follow the manual’s handling warnings.

Search, Contents Navigation and PDF Files

Text search and diagram detail: Text search is available in all three PDFs. Embedded bookmarks lead to language-specific contents pages rather than directly to repair sections. Small wiring labels are readable with zoom. The 2001 wiring-page heading has overlapping text, while the circuit remains readable when enlarged.

The 1,867-page set contains three printable PDFs, each with English, French and German text, packaged in one ZIP download. The totals include 25 front-matter pages and one back cover per manual, plus two blank pages in the 2001 file and one in the 2002 file.

Engine, Chassis and CDI/TPS Service

The following selected service topics show the scope of the manuals. Additional subjects include starting and break-in, decompression-control adjustment, and cleaning and storage.

• Engine repair: Step-by-step procedures for engine removal, cylinder-head and valve service, piston inspection, camshaft installation, and crankcase separation.

• Clutch and transmission: Clutch disassembly and inspection, kickstarter and shift-shaft service, gear inspection, and transmission reassembly.

• Carburetor service: Keihin FCR MX39 removal, disassembly, float-height inspection, accelerator-pump checks, and jetting guidance.

• Cooling and lubrication: Radiator-cap pressure testing, coolant replacement, water-pump seal and shaft inspection, and oil-pump service.

• Brakes and chassis: Brake bleeding, caliper and master-cylinder service, wheel-bearing replacement, steering-head adjustment, and swingarm linkage inspection.

• Suspension: Front-fork disassembly, seal replacement, oil-level setting, and spring, rebound, and compression-damping adjustments.

• Ignition and TPS diagnosis: No-spark inspection charts, ignition-coil and CDI-magneto tests, throttle-position-sensor checks, connector illustrations, and wiring diagrams.

The owner sections explain operation and routine checks; internal repair work is suited to experienced mechanics equipped with precision measuring tools and the specified service tools.

Engine Inspection and Assembly References

Exploded-view diagrams and job instruction charts illustrate assembly order and the extent of removal, making the manuals a practical reference for daily shop-floor tasks. Inspection sections distinguish normal dimensions from service limits for valve guides, piston rings, crankshaft runout, and other wear points.

Camshaft procedures include Plastigauge clearance checks and timing-chain alignment. The handling notes explain how uneven cam-cap tightening can damage the cylinder head, caps, and camshafts.

Crankcase work identifies the separating tool 90890-01135 and the crankshaft installation tools. Transmission assembly views show gear and shift-fork placement, with model-year gear data and final shift-operation checks. Lubrication diagrams trace the engine’s oil passages.

Carburetor Tuning and Race Setup

The tuning chapters relate atmospheric conditions and throttle opening to mixture changes. Charts show the operating ranges of the pilot circuit, jet needle, and main jet, while symptom tables connect poor throttle response and plug appearance with areas to inspect.

Optional jet, needle, sprocket, and suspension-spring tables include part numbers. Suspension charts distinguish spring changes from damping adjustments and relate them to track conditions and rider feedback.

Electrical Fault Tracing

The map-controlled CDI explanation connects engine speed and throttle opening with ignition timing. Separate ignition and TPS inspection charts organize connection, coil, neutral-switch, and CDI checks, with test-lead illustrations alongside the electrical specifications.

Edition-specific TPS adjustment: The 2000 and 2001 manuals use a calculated resistance setting. The 2002 edition specifies an output-voltage adjustment and includes connector-probing cautions.

Fork and Chassis Service Detail

Fork procedures extend to damper-rod inspection, bushing and seal installation, and oil-level adjustment. The assembly notes identify the risk of damaging the internal valve through incorrect damper-rod handling.

Brake sections include piston and seal inspection, hose positioning, and post-assembly leak checks. Steering and swingarm procedures cover bearing condition, installation, and lubrication points.

Preview: Valve Clearance and Ignition Test Data

Cold intake-valve clearance is 0.15–0.20 mm in the 2000 manual and 0.10–0.15 mm in the 2001 and 2002 manuals. The adjustment sections pair these specifications with valve-pad selection tables.

For ignition diagnosis, all three editions list source coil 1 resistance at 720–1,080 ohms at 20°C (68°F), with connector illustrations identifying the test leads.