Yamaha TT-R90 & TT-R90E Owner's Service Manual Set, 1999–2005 (P/N 5HN-28199-8A)

These editions contain overlapping repair content for kickstart and electric-start configurations. Match the model code, market, and starting system to the relevant edition before selecting specifications or electrical tests.

PDF Search, Bookmarks and Wiring Detail

Text search and diagram navigation: All seven PDFs have searchable text. In the M, N, P, R, E(R), and T files, chapter bookmarks lead to contents pages rather than directly to the procedures. The V file also has working section-level bookmarks. Small wiring labels require zooming for comfortable reading.

The ZIP contains seven printable PDFs totaling 2,252 pages, with English, French, and German text. This total includes covers, memo and blank pages, and seven added introductory pages—one per file.

Engine, Chassis and Electrical Service Coverage

The following selected coverage highlights outline the repair content. Other topics include control operation and pre-ride inspections.

• Engine repair: Step-by-step procedures cover cylinder-head removal, valve-seat inspection and lapping, piston and ring checks, camshaft timing, and timing-chain tensioner installation.

• Clutch and transmission: Wet multi-disc and automatic centrifugal clutch service, clutch-release adjustment, and transmission disassembly with shift-fork and shift-cam inspection.

• Carburetor service: Mikuni VM16SH removal and teardown, main-jet identification, float and needle-valve inspection, and fuel-level adjustment.

• Chassis repair: Front-fork damper rods and oil seals, wheel bearings, drum brakes, steering-head bearings, and swingarm removal.

• Electrical diagnosis: CDI ignition fault tracing, wiring diagrams, and TT-R90E-specific starting and charging diagnosis, including starter-motor repair.

The repair sections are written for mechanics using the specified tools and measuring equipment. Owners can use the operating and routine-maintenance sections; marked maintenance tasks require dealer service and technical skills.

Engine Teardown and Internal Inspection

Factory checks cover cylinder-head distortion, valve-seat width, camshaft and rocker-arm wear, and connecting-rod big-end clearance. Lower-end coverage includes crankcase separation and crankshaft inspection.

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.

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.

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.

Ignition, Starting and Charging Diagnosis

The Ignition System troubleshooting chart separates spark, switch, ignition-coil, pickup-coil, and source-coil checks. These tests help distinguish a switching or wiring fault from a component fault during no-spark diagnosis.

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.

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.

Selected Valve, Piston and Carburetor Specifications

For the TT-R90(V) and TT-R90E(V), the V edition specifies a cold intake-valve clearance of 0.05–0.09 mm. Its piston inspection data lists a standard piston-to-cylinder clearance of 0.025–0.045 mm and a service limit of 0.15 mm.

For the same models’ Mikuni VM16SH carburetor, the specified float height is 15.5–16.5 mm.