2003–2006 Yamaha TTR-90(R) Owner's Service Manual (P/N 5HN-28199-83)

• Covers the 2003-2006 Yamaha TT-R90 and TT-R90E kick-start and electric-start off-road motorcycles, with factory model-code assignments for the USA, Canada, Europe, Australia, New Zealand, and South Africa.
• Five Yamaha Owner's Service Manual PDFs total 1,746 pages and retain the original English, French, and German publication content.
• Engine repair coverage spans carburetor service, cylinder-head and cam-timing work, valves, piston and rings, clutch, oil pump, crankshaft, and transmission inspection, disassembly, reassembly, and adjustment.
• Chassis repair sections address front and rear drum-brake wheels, wheel bearings, front-fork teardown, handlebar and steering service, swingarm removal, rear-shock removal, and spring-preload adjustment.
• TT-R90E-specific material covers the starter clutch, starter motor, battery, fuse, neutral switch, starting-circuit cut-off relay, starter relay, and charging system, with fault-isolation charts and component test data.
• Factory reference material includes model-specific cable-routing and wiring diagrams, exploded assembly views, job-instruction charts, torque tables, capacities, wear limits, clearance data, and electrical test specifications.

Coverage and Publication Identity

The set separates the two 2003 configurations, then combines both starting-system variants for each later model year. The 2003 TT-R90(R) kick-start manual is a 288-page PDF, Yamaha P/N 5HN-28199-83, first edition April 2002; the TT-R90E(R) electric-start volume is 340 pages, P/N 5HN-28199-8A, first edition September 2002. The combined TT-R90(S)/TT-R90E(S) manual is 364 pages, P/N 5HN-28199-84, first edition March 2003. TT-R90(T)/TT-R90E(T) is covered in a 364-page manual, P/N 5HN-28199-85, first edition April 2004, while TT-R90(V)/TT-R90E(V) uses a 390-page manual, P/N 3P2-28199-80, first edition April 2005.

Each volume follows six Yamaha chapters: General Information, Specifications, Regular Inspection and Adjustments, Engine, Chassis, and Electrical. Identification pages show the VIN and engine serial-number locations, plus the TT-R90E key-identification number.

The 2003 volumes identify 5HNB/5HNC/5HND for the TT-R90 and 5HNE/5HNF/5HNG for the TT-R90E. The 2004 manual uses 5HNH/5HNJ/5HNK and 5HNL/5HNM/5HNN. These three-code groups follow the regional order USA, Europe/Australia/New Zealand/South Africa, and Canada. For 2005, the codes are 5HNR/5HNS for the kick-start machine and 5HNT/5HNU/5HNV for the electric-start version. The 2006 manual lists 5HNW/5HNX and 3P21/3P22/3P23. The 2005 and 2006 kick-start groups omit a U.S. code, while the electric-start groups retain all three regions. Fitment is organized by factory model code, so that code should be matched before selecting the applicable repair section.

Engine, Transmission, and Tuning Work

These are true owner's service manuals, not operation-only handbooks. Exploded views and job charts organize the repair work. Top-end and fuel-system procedures cover carburetor removal and fuel-level setting, cylinder-head and cam-timing work, rocker arms, valve inspection and lapping, and piston-ring installation. Lower-end coverage addresses clutch inspection and release adjustment, kick and shift shafts, oil-pump inspection, rotor removal, crankcase separation, crankshaft measurement, and mainshaft/drive-axle transmission service. TT-R90E chapters add starter-clutch inspection and starter-motor disassembly and repair.

Routine maintenance sections cover service intervals, pre-operation inspection, throttle-cable adjustment, air-filter cleaning, engine-oil service, pilot-air-screw and idle-speed adjustment, and valve-clearance adjustment. Brake and drive-chain setup, steering-head adjustment, spoke and wheel inspection, lubrication, spark-plug checks, battery charging, and fuse testing are also documented. The 2006 volume adds cleaning and storage guidance.

Chassis, Electrical Diagnosis, and Reference Aids

The chassis chapters document wheel removal, brake-shoe and drum inspection, bearing replacement, fork removal and disassembly, oil-seal installation, steering-bearing service, swingarm removal, and rear-shock preload changes. Rear-shock coverage is limited to inspection, removal, and spring adjustment rather than internal gas-shock overhaul.

Diagnostic support goes beyond a single schematic. The set contains separate TT-R90 and TT-R90E cable-routing and wiring diagrams, an ignition-system no-spark chart, electric-start fault tree, charging-system test chart, and carburetor-heater diagnostic chart. Tool callouts provide North American and 90890-series equivalents. Examples include the rocker-shaft slide hammer YU-1083-A / 90890-01084 and 90890-01085, valve-spring compressor YM-4019 / 90890-04019, flywheel puller YU-33270-B / 90890-01362, damper-rod holder YM-1300 / 90890-01294, and pocket tester YU-3112-C / 90890-03112.

The manual specifically warns against turning the crankshaft while installing the camshaft, since damage or incorrect valve timing can result. It also directs the technician to keep crankcase sealant out of the oil gallery, where blockage can compromise lubrication. Wheel, fork, steering, swingarm, and shock procedures require the motorcycle to be securely supported; the publications also carry fuel, battery, and hot-engine precautions for repair work.