2001 Yamaha YZ85(P)/LC, YZ85LW(P) Owner's Service Manual (P/N 5PA-28199-80)

Yamaha’s Owner’s Service Manual 5PA-28199-80, first edition April 2001, covers the YZ85(P)/LC and YZ85LW(P) liquid-cooled, 2-stroke competition minibikes.

Supplied as a 504-page PDF, with English, French, and German text in one file.

• Engine repair: Cylinder head, cylinder and piston service, engine removal, crankcase separation, crankshaft inspection, and reassembly.

• Clutch and transmission: Wet multi-disc clutch repair, primary gears, kickstarter mechanism, and six-speed transmission, shift cam, and shift fork inspection.

• Carburetor and intake: Keihin PWK28 disassembly, float-height checks, reed valve inspection, and mixture-setting guidance tied to engine symptoms.

• Cooling system: Radiator removal, cap-opening-pressure and cooling-system leak tests, plus water-pump shaft, bearing, and seal service.

• Brakes and suspension: Caliper and master-cylinder repair, brake bleeding, fork overhaul, steering bearings, swingarm linkage, and rear-shock spring service.

• Ignition diagnosis: Wiring diagram, connector views, spark-gap testing, and separate checks for the ignition coil, pickup coil, and both CDI magneto charging coils.

The repair sections suit mechanics and experienced owners equipped for precision measurements and internal engine work; Yamaha recommends dealer service for the front fork.

Model Codes and Wheel Variants

YZ85: Code 5PA1 covers the USA, Canada, Europe, New Zealand, and South Africa; 5PA2 identifies the Australian version. Wheel sizes are 17 inches front and 14 inches rear.

YZ85LW: Code 5SH1 covers Europe and New Zealand; 5SH2 identifies Australia. This larger-wheel version uses a 19-inch front wheel and 16-inch rear wheel.

Specifications distinguish final-drive gearing, chain length, fork position, and model- and market-specific suspension settings. Machine-identification pages show VIN, engine serial number, and model-label locations.

Top-End and Internal Engine Repair

Engine inspection covers cylinder-head warpage, piston and ring wear, crankshaft runout, and connecting-rod clearances. The piston/cylinder matching chart relates A–D cylinder marks to piston grades, helping select a compatible replacement during a top-end repair.

Exploded clutch and transmission views accompany disassembly and reassembly procedures. Details include clutch-plate inspection and shift-fork wear and movement checks.

The special-tool list identifies the crankcase separator YU-1135-A / 90890-01135 and clutch holder YM-91042 / 90890-04086, with regional tool-number conventions.

The manual lays out standardized torque values, fluid capacities, and dimensional tolerances, alongside lubrication requirements and wear limits.

Carburetor Tuning and Cooling-System Service

Carburetor charts relate throttle opening to jet and needle selection, with setting examples for weather and track conditions. Symptom tables address poor acceleration, fouled spark plugs, and irregular running.

Routine maintenance includes race-based inspection schedules, air-filter care, and exhaust and silencer service, including packing replacement.

Water-pump inspection addresses coolant discoloration and milky transmission oil. Assembly cautions explain how impeller-shaft installation can damage the seal lip or displace its spring.

Fork, Linkage, and Brake Service

Front-fork exploded views cover damper rods, base valves, bushings, and seals. The assembly notes identify how a dropped damper rod can damage the internal valve.

Suspension-setting charts address bottoming, harshness, and poor traction, supported by spring options and part numbers for each model and market. Swingarm procedures cover the relay arm, connecting rod, bearings, and bushings.

Rear-shock coverage includes removal, inspection, spring replacement, and adjustment. Internal overhaul of the nitrogen-filled shock cylinder and reservoir is outside the documented scope.

Brake sections cover piston and seal inspection, hydraulic bleeding, and leak checks. Follow the manual’s safety precautions for hot coolant and the pressurized rear shock.

CDI Ignition Troubleshooting

The ignition inspection flowchart and tester-connection views help narrow down a no-spark fault before CDI-unit replacement. Electrical tables distinguish primary and secondary ignition-coil resistance, pickup-coil checks, and the two charging coils.

Ignition-timing inspection and adjustment are documented, with cable-routing diagrams showing harness, hose, and control-cable placement.

PDF Format and Navigation

The total includes both covers, 24 preliminary pages, and three “Memo” pages. No separate supplements are included.

Text search: Body text and tables are searchable; lettering within diagrams is not consistently searchable.

Navigation: Embedded bookmarks lead to the cover and contents pages. Linked contents entries provide access to the service sections.

Diagram readability: Small wiring and connector labels are readable when enlarged.