2000–2002 Yamaha TT-R90(M) 5HN1, 5HN2, 5HN3, and 5HN4 Owner's Service Manual (P/N 5HN-28199-80)

• Three complete year-specific PDFs cover the 2000 TT-R90(M), 2001 TT-R90(N), and 2002 TT-R90(P), model codes 5HN1–5HN9 and 5HNA. Yamaha P/Ns: 5HN-28199-80, 5HN-28199-81, and 5HN-28199-82. 863 pages total — 2000: 287; 2001: 288; 2002: 288.
• Engine repair coverage includes carburetor removal and fuel-level adjustment, cylinder-head and cam-timing work, rocker arms, valves and springs, cylinder/piston inspection, oil-pump service, and crankcase/crankshaft repair.
• Clutch and transmission procedures cover the wet multi-disc clutch, centrifugal primary clutch, kick axle, shift shaft, shift forks and cam, and constant-mesh transmission removal, inspection, and reassembly.
• Chassis service addresses drum brakes, wheel bearings, fork-seal and damper-rod work, steering-head adjustment, swingarm and rear-shock removal, drive-chain setup, spokes, and wheel inspection.
• Electrical fault-finding includes the wiring diagram, cable-routing views, ignition inspection chart, spark/coil/CDI magneto tests, and carburetor-heater and thermo-switch diagnosis.
• Reference sections supply component-specific torque tables, capacities, wear limits, clearances, electrical test specifications, maintenance schedules, and Yamaha special-tool part numbers.

Exact Year and Market Coverage

This is a set of three full Yamaha Owner’s Service Manuals, not one base book followed by short annual supplements. The 2000 TT-R90(M) manual identifies 5HN1 for U.S. machines outside California, 5HN2 for California, 5HN3 for Europe and Oceania, and 5HN4 for Canada. The 2001 TT-R90(N)/NC publication assigns 5HN5 to the U.S., 5HN6 to Europe, Australia, and New Zealand, and 5HN7 to Canada. For 2002, the TT-R90(P)/PC manual covers 5HN8 for the U.S., 5HN9 for Europe, Australia, New Zealand, and South Africa, plus 5HNA for Canada.

The identification pages locate the VIN on the right side of the steering-head pipe, the engine serial number on the raised left-side engine boss, and the model label beneath the rider’s seat. All three are first editions—July 1999, May 2000, and April 2001 respectively. Each follows the same six-chapter structure while retaining year-specific specifications, routing, tool references, and regional notes. English pages are accompanied by French and German translations.

What the Engine Chapters Actually Cover

The repair content goes well beyond operation and routine maintenance. Yamaha documents the 89 cm³ air-cooled SOHC single, Mikuni carburetor, wet-sump lubrication system, wet multi-disc clutch, centrifugal primary clutch, and three-speed gearbox through removal layouts, inspection criteria, and assembly notes.

Carburetor pages cover disassembly, jet, float, and needle-valve checks, reassembly, and fuel-level setting. Top-end repair includes cylinder-head removal, timing alignment, camshaft and rocker-arm work, valve and spring removal, valve-guide and seat inspection, cylinder/piston measurements, ring and piston-pin checks, and installation. Lower-end sections continue through clutch inspection, kick and shift mechanisms, oil-pump disassembly, CDI magneto and stator removal, crankcase separation, crankshaft inspection, and shift-fork, shift-cam, main-axle, and drive-axle service.

Chassis and Electrical Diagnosis

Chassis repair covers the wheel and drum-brake assemblies, wheel bearings, front fork, handlebar, steering, swingarm, and rear shock. Fork content includes oil-seal and damper-rod removal and installation. Rear-shock coverage stops at removal, inspection, and spring-preload adjustment; it is not an internal damper overhaul manual. Regular inspection sections add brake and drive-chain adjustment, spoke tightening, steering-head checks, lubrication points, and spark-plug service.

Electrical diagnosis is built around factory inspection charts. The ignition chart moves from spark testing and harness connections through the engine-stop switch, ignition coil, pickup coil, source coil, and CDI unit. A separate carburetor-heating chart covers the thermo switch, heater, CDI magneto source coil, and rectifier/regulator rather than leaving the technician with a schematic alone.

Exploded Views, Tools, and Specifications

Named visual references include the Cable Routing Diagram, Clutch Removal, Crankcase Separation and Crankshaft Removal, Shift Fork, Shift Cam and Transmission Removal, Front Wheel and Front Brake / Rear Wheel and Rear Brake, and Electrical Components and Wiring Diagram. Yamaha’s “Extent of removal” layouts pair the exploded views with part names, quantities, removal stages, and cross-references.

The special-tool lists identify clutch holding tool 90890-04086, flywheel puller 90890-01362, ignition checker 90890-06754, and fork-seal driver components 90890-01184/01186, with applicable U.S./Canada tool numbers. Specifications cover fastener torque, capacities, adjustment data, wear limits, clearances, spring and chain checks, and electrical testing. Use the volume matching the exact year and model code, since tool references and some service data changed across the editions.

Repair-Critical Cautions

The camshaft section warns that turning the crankshaft during installation can cause damage or leave valve timing incorrect. The lubrication notes also caution against unsuitable additives and energy-conserving oils because the shared engine oil can make the clutch slip. Before wheel, fork, swingarm, or engine repair, support the minibike securely and keep gasoline work away from sparks, flames, and hot engine parts.