2001 Yamaha YZ250FN Owner's Service Manual

Yamaha's 2001 YZ250FN Owner's Service Manual covers the 5NL-series competition models: YZ250FN (USA, 5NL1), YZ250FLC (Europe, 5NL2), and YZ250F(N) (Canada, Australia, New Zealand and South Africa, 5NL4). Its seven chapters combine operating information, scheduled inspection, repair procedures and race setup.

Search and wiring detail: The service chapters have searchable text; the cover has no text layer. Embedded bookmarks open the chapter starts and wiring diagram. Small wire-color and connector labels are readable when zoomed in.

• Engine repair: Engine removal, crankcase separation, cylinder-head and valve-train service, camshaft timing, and cylinder and piston inspection.

• Clutch and transmission: Wet-clutch repair, primary-drive and balancer service, plus inspection and assembly of the kick shaft, shift shaft, shift forks and shift cam.

• Fuel system: Keihin FCR-MX37 disassembly, accelerator-pump inspection, float adjustment, starter-plunger inspection and carburetor tuning.

• Cooling and lubrication: Radiator pressure testing, water-pump service, oil-pump inspection, oil-strainer maintenance and lubrication-system checks.

• Chassis: Front-fork overhaul, rear-shock removal and spring service, swingarm and steering-head repair, wheel-bearing replacement, brake-caliper service and brake bleeding.

• Electrical diagnosis: Map-controlled CDI operation, ignition troubleshooting, throttle position sensor testing and adjustment, wiring diagrams and component-location views.

Owners can use the operating and routine-maintenance sections; the internal repair procedures are suited to mechanics with precision measuring equipment and the listed special tools.

Engine, Valve Train and Transmission

Valve service goes beyond clearance checks: intake and exhaust pad selection tables accompany camshaft-to-cap clearance measurements, valve-guide replacement and valve-seat refacing. A cylinder-head/valve-lifter color-matching chart supports component selection.

The camshaft section warns that uneven cap-bolt tightening can damage the cylinder head, caps and camshafts.

Bottom-end coverage includes crankshaft runout and connecting-rod checks, gear engagement inspection and transmission assembly checks. The special-tool list identifies the crankcase separator as YU-1135-A / 90890-01135 and the clutch holder as YM-91042 / 90890-04086.

Keihin Carburetor Setup

European carburetor specifications list ID 5NL2 10 and the OBEJP-4 needle; other covered markets use ID 5NL1 00 and OBELP-4. These distinctions help match the tuning data and setting parts to the correct regional configuration before selecting replacement jets or needles.

Carburetor setting charts connect symptoms and throttle position with jetting changes, including the leak jet's role in accelerator-pump delivery. Cold- and hot-start controls, manual decompression, break-in and race-based maintenance intervals are also explained.

Cooling and Dry-Sump Lubrication

Cooling sections include radiator-cap and system pressure checks, plus impeller-shaft, bearing and seal inspection. Lubrication coverage follows the frame oil tank, strainers, oil-delivery pipes and trochoid oil pump, with rotor-clearance limits and oil-pressure inspection.

Suspension, Steering and Brakes

Suspension specifications for Europe and the other covered markets are listed separately, including spring types and baseline damping settings. The tuning chapter adds spring-selection tables, ride-height setup, secondary gearing options and symptom-based suspension setting charts.

Exploded views and job instruction charts accompany fork, swingarm-linkage, steering-bearing and brake repairs. Yamaha recommends dealer service for the front fork and warns that dropping the damper rod can damage its internal valve.

Rear-shock coverage includes spring and bearing service, but not internal rebuilding of the nitrogen-charged damper. Observe the manual's precautions for pressurized suspension components and brake work.

Ignition and TPS Fault Finding

Wiring and cable-routing diagrams are paired with ignition and throttle position sensor (TPS) troubleshooting charts. Test information covers the stop and neutral switches, pickup and charging coils, ignition-coil resistance, TPS input voltage and replacement adjustment.

The 3-D ignition-timing image explains control by engine speed and throttle opening; it is illustrative, not an actual calibration map.

Factory Tables and PDF Contents

Component-specific torque tables, fluid capacities, wear limits and electrical test specifications support the repair sections. The file is a printable, English-language 295-page PDF, comprising 283 chapter pages plus 12 opening pages: one cover and 11 pages of introductory material, index and contents, all already included in the total.