1999–2005 Yamaha TT-R90E(R) Owner's Service Manual (P/N 5HN-28199-8A, 5HN-28199-81)

• Covers kickstart TT-R90 and kick/electric-start TT-R90E configurations, with separate editions and market-specific model-code tables.
• Engine repair coverage includes cylinder-head removal, valve-seat inspection and lapping, piston and ring checks, camshaft timing, and timing-chain tensioner installation.
• Details wet multi-disc and automatic centrifugal clutch service, clutch-release adjustment, and transmission disassembly with shift-fork and shift-cam inspection.
• Mikuni VM16SH carburetor coverage runs from removal and teardown to main-jet identification, float and needle-valve inspection, and fuel-level adjustment.
• Chassis procedures cover front-fork damper rods and oil seals, wheel bearings, drum brakes, steering-head bearings, and swingarm removal.
• Electrical sections provide CDI ignition fault tracing, wiring diagrams, and TT-R90E-specific starting and charging diagnosis, including starter-motor repair.

Included Editions and Model Coverage

This seven-file set contains Yamaha Owner’s Service Manual editions totaling 2,252 PDF pages. The files include English, French, and German text, overlapping repair content, covers, and one added third-party introductory page per file.

Dates identify publication editions. Match the motorcycle’s model code and market to the relevant manual before selecting specifications or electrical tests.

The TT-R90E(R) edition identifies 5HNE for the USA, 5HNF for Europe, Australia, New Zealand, and South Africa, and 5HNG for Canada. Its model names are TT-R90ER in the USA, Canada, Australia, and New Zealand, and TT-R90E in Europe and South Africa.

The V edition distinguishes kickstart models 5HNW/5HNX from electric-start models 3P21/3P22/3P23. The latter map to the USA, Europe/Australia/New Zealand/South Africa, and Canada, respectively. Earlier editions also identify California-specific configurations.

Engine Teardown and Internal Inspection

The engine chapters detail teardown, inspection, and reassembly of the 89cc air-cooled SOHC single. Factory checks cover cylinder-head distortion, piston-to-cylinder clearance, valve-seat width, camshaft and rocker-arm wear, and connecting-rod big-end clearance.

Lower-end coverage includes crankcase separation, crankshaft inspection, and the 3-speed constant-mesh gearbox. The “Oil Pump” exploded view accompanies trochoid rotor-clearance checks and rotary-filter and oil-strainer service. “Shift Fork, Shift Cam and Transmission” views support shaft disassembly and gear-selection checks after assembly.

The camshaft-installation cautions address crankshaft movement that can cause damage or incorrect valve timing. Valve-assembly notes also warn that excessive force on the valve tip can damage the valve.

Chassis Service and Maintenance Limits

Routine service intervals are mapped out in maintenance charts. Service procedures cover valve clearance, spark-plug condition and gap, drive-chain alignment, and spoke and rim checks. Control-cable adjustment and U.S.-market spark-arrester cleaning are also included. The “Cable Routing Diagram” pages identify cable, hose, and electrical-lead paths for reassembly.

Monocross rear-suspension coverage includes shock removal, operating and leakage checks, pivot inspection, and spring-preload adjustment. Rear-shock coverage stops short of internal damper overhaul.

Electrical Diagnosis and Factory Specifications

The “Ignition System” troubleshooting chart separates spark, switch, ignition-coil, pickup-coil, and source-coil checks. TT-R90E coverage follows the neutral switch, starting-circuit cut-off relay, and starter relay through the “Electric Starting System” schematic. Starter inspection extends to brushes, the commutator, and armature resistance rather than stopping at motor replacement.

The “Carburetor Heating System” troubleshooting chart covers the heater, thermo switch, lighting coil, and rectifier/regulator. Temperature-dependent thermo-switch tests distinguish it from ordinary carburetor cleaning. Maintenance-free battery charging charts and charging-system tests support electrical repair on equipped models.

Dedicated tables provide engine and chassis tightening torques, lubricant grades and capacities, wear limits, adjustment data, and electrical test specifications. The V edition’s tool references include valve spring compressor YM-4019 / 90890-04019 and clutch holding tool YM-91042 / 90890-04086, with U.S./Canadian and international tool numbers.

Working on motorcycle engines involves inherent risks to personal safety and equipment integrity. Always adhere strictly to the factory procedures and consult a certified Yamaha technician if you are unsure about evaluating internal wear or structural limits.