2000 Yamaha XN125 / XN150 Scooter Service & Repair Manual (P/N 5MF1-AE2)

This service manual covers the 2000–2001 Yamaha XN125 and XN150 Teos scooters. It is MBK Industrie's second edition, dated April 2001, carrying document code 5MF1-AE2.

Text search and circuit detail: The PDF has searchable text and ten bookmarks linking to the nine chapters and the overall wiring diagram. Small wire-color codes and connector labels require zooming.

• Engine repair: Liquid-cooled SOHC engine removal, valve-clearance adjustment, cylinder-head overhaul, piston and cylinder inspection, crankcase separation, and crankshaft checks.

• Belt drive and transmission: V-belt replacement, primary and secondary sheave service, dry centrifugal automatic clutch inspection, clutch-shoe replacement, and reduction-gear removal.

• Fuel system: Teikei carburetor disassembly and reassembly, fuel-level and idle-speed adjustment, auto-choke testing, and fuel-cock inspection.

• Cooling system: Radiator removal, thermostat testing, water-pump inspection and installation, coolant replacement, and cooling-system diagrams.

• Brakes and chassis: Front disc and rear drum brake service, hydraulic bleeding, telescopic front-fork overhaul, steering-head bearings, and rear-shock inspection.

• Electrical diagnosis: CDI ignition, electric starting and charging circuits, lighting and signaling faults, and carburetor-heater troubleshooting with circuit diagrams.

• Service references: Maintenance schedules, general and component-specific torque tables, fluid capacities, lubrication points, wear limits, service symbols, adjustment data, and electrical test specifications.

Written primarily for Yamaha and MBK dealers and their qualified mechanics, this manual assumes an understanding of mechanics and the repair techniques used on these scooters.

Engine Overhaul and Inspection

Engine overhaul extends to valve-guide replacement, valve-seat lapping and timing-chain tensioner checks. Compression-test interpretation, crankshaft runout and connecting-rod clearance measurements help evaluate engine condition.

Exploded diagrams are paired with job instruction charts showing part names and removal order, plus lubrication and replacement symbols. These references let a mechanic cross-check component identification and assembly requirements together during repair.

Engine lubrication diagrams and oil-pump inspection criteria cover the wet-sump lubrication system.

Clutch Variants and Reduction Gears

Separate specifications distinguish the two models' clutch-housing dimensions, clutch springs and secondary reduction ratios. These differences help match inspection criteria to the correct version before selecting replacement parts.

Secondary-sheave service identifies clutch spring holder 90890-01337 and holder arm 90890-01464. The transmission section provides removal and installation references for the reduction gears and shafts.

Teikei Carburetor Adjustment

The XN125 uses the TK 5DS/1, while the XN150 uses the TK 5KD/1. Separate jetting and pilot-screw specifications accompany inspection of the diaphragm and needle-valve components.

Fuel-system repair also covers the accelerator pump and auto-choke starter plunger. Fuel-level gauge 90890-01312 is identified for float-chamber measurement and adjustment.

Thermostat, Radiator and Water Pump

Cooling System Diagrams show hose routing, while thermostat tests and radiator-fan troubleshooting address temperature-control faults. The water-pump section specifies assembly replacement for damaged impeller or oil-seal components.

Brake Hydraulics and Front-Fork Repair

Front brake coverage extends to master-cylinder and caliper disassembly, inspection and reassembly. The manual warns that solvents can swell and distort the caliper piston seals.

Fork instructions cover damper-rod removal, seal replacement and oil-level setting. A specific caution explains that bottoming the inner tube during disassembly can damage the oil-flow stopper.

Steering-head procedures include bearing and race replacement. Rear-shock checks apply to the unit-swing rear suspension, with replacement criteria for the shock assembly, bushings and dust seals.

Electrical Fault Charts and Wiring

Fault charts address no spark, a starter motor that will not turn, charging failure, and lighting or signaling faults. CDI unit diagnosis is supported by ignition-coil, pickup-coil and source-coil test specifications.

Charging checks cover the stator coil and rectifier/regulator. Starter-motor repair includes armature resistance, commutator inspection, brush wear and brush spring-force checks.

The Ignition System and Carburetor Heating System circuit diagrams accompany the XN125-150 Wiring Diagram, which marks optional anti-theft and sidestand-switch connections. Cable Routing drawings show harness and control-cable installation.

Follow the manual's specifications and workshop precautions for hydraulic brake work, hot coolant and ignition-system testing.

English PDF and Included Pages

This is one printable, 259-page English PDF, with the original cover, five preliminary pages, chapter dividers, contents pages and final oversized wiring diagram included in that total.