2004 Yamaha TT-R90(T)/TT-R90E(T) Owner's Service Manual (P/N 5HN-28199-85)

Yamaha's 2004 TT-R90(T)/TT-R90E(T) Owner's Service Manual covers the kick-start and electric-start off-road models. The original publication is 5HN-28199-85, first edition, April 2004.

364 pages in one PDF, with English, French, and German content.

• Engine repair: Cylinder-head removal, camshaft and rocker-arm service, valve-seat inspection and lapping, cylinder and piston checks, and timing-chain installation.

• Clutch and transmission: Wet multi-disc and centrifugal clutch service, clutch-release adjustment, kick axle teardown, crankcase separation, and shift fork, shift cam, and transmission work.

• Lubrication and magneto: Oil pump disassembly, rotary-filter and strainer inspection, CDI magneto removal, and TT-R90E starter clutch checks.

• Fuel and maintenance: Mikuni VM16SH carburetor disassembly and adjustment, float-height and fuel-level checks, and periodic maintenance and lubrication charts.

• Chassis and brakes: Front fork disassembly and seal replacement, steering-head service, swingarm and rear-shock removal, wheel-bearing replacement, and drum-brake inspection.

• Electrical diagnosis: Model-specific wiring diagrams, ignition and carburetor heating tests, and TT-R90E electric starting and charging troubleshooting, including starter-motor repair.

The repair procedures are written for mechanics; owners also get operating and routine maintenance guidance, with specialist jobs marked for Yamaha dealer service.

Model Codes and Regional Coverage

The model table identifies TT-R90 codes 5HNR for Europe, Australia, New Zealand, and South Africa, and 5HNS for Canada. TT-R90E codes are 5HNT for the USA, 5HNU for Europe, Australia, New Zealand, and South Africa, and 5HNV for Canada.

Engine, Clutch, and Transmission Repair

Job instruction charts and exploded views show disassembly scope, lubrication points, and replacement items for the 89 cc four-stroke engine. Component sectional views and inspection tables cover valve clearances, piston rings, camshaft wear, and crankshaft runout.

Clutch checks cover plate wear, warpage, and centrifugal shoe wear. Transmission pages show main- and drive-axle disassembly, shift fork and shift cam installation, and final operating checks for the constant-mesh three-speed transmission.

The camshaft installation notes warn that crankshaft movement during this work can cause damage or incorrect valve timing. Specified tools include the clutch holder YM-91042 / 90890-04086 and flywheel puller YU-33270-B / 90890-01362.

Reference tables provide compression data, drivetrain reduction ratios, fluid capacities, and component-specific torque values, including the clutch boss.

Carburetor and Routine Adjustments

Carburetor repair includes needle-valve and seat inspection, jet-needle checks, and throttle-slide inspection. Routine adjustments cover the pilot air screw, idle speed, and valve clearances, with a separate US spark arrester cleaning procedure.

Wheels, Steering, and Suspension

The steel tube backbone chassis is documented with frame geometry, fork-oil specifications, brake-lining wear limits, and wheel-runout data. Separate handlebar illustrations and cable routing diagrams distinguish the two models.

Monocross rear-shock coverage includes inspection, removal, and spring-preload adjustment; it does not include an internal shock-rebuild procedure.

Ignition, Starting, and Charging Tests

Separate TT-R90 and TT-R90E wiring diagrams include component locations, connector views, and wire-color codes. Ignition and electric-start troubleshooting flowcharts connect pickup-coil, switch, and relay tests to fault isolation, helping diagnose a no-spark or no-crank condition before replacing electrical parts.

TT-R90E coverage includes the 12V starter assembly, starting circuit cut-off relay and neutral-switch operation, battery charging charts, and charging-system tests. Starter-motor repair covers commutator, armature, brush, and brush-spring inspection.

Carburetor heating checks distinguish the models' thermo-switch behavior and lighting-coil specifications. The MF battery section warns that high-rate charging can overheat the battery and damage its plates.

Follow the documented factory procedures before applying torque or handling fuel components; support the machine securely during wheel and suspension work.

PDF Languages, Search, and Navigation

The total includes 25 preliminary pages, including the front cover, seven memo pages, three maintenance-record pages, one blank page, and the back cover. English content is interleaved with French/German pages, and the PDF has searchable text. Chapter bookmarks lead to contents pages rather than chapter openings; small wiring and connector labels require zooming.