2003–2007 Kawasaki KX125 & KX250 Service Manual PDF

This Kawasaki factory service manual covers 2003–2007 KX125 and 2003–2004 KX250 two-stroke competition motorcycles. Model coverage comprises KX125-M1, M2, M3, M6F and M7F, plus KX250-M1 and M2; the Model Application table identifies their beginning frame numbers.

Text search and diagram detail: Service text is searchable, with bookmarks for all 15 chapters and both wiring diagrams. The cover and text within image-based diagrams, including the ignition troubleshooting flowchart, are outside text search. Small wiring labels are best read with zoom.

• Engine repair: Cylinder compression testing, piston and ring service, KIPS exhaust-valve removal and installation, engine removal and installation, and crankcase splitting.

• Clutch and transmission: Wet multi-disc clutch inspection and replacement, ratchet-type shift mechanism service, and transmission shaft disassembly and reassembly.

• Fuel system: Carburetor rebuilding and service-fuel-level adjustment, with model-specific jetting specifications, throttle-cable checks, and reed-valve inspection.

• Cooling system: Pressure testing, radiator-cap inspection, water-pump shaft and seal replacement, coolant changes, and air bleeding.

• Suspension: Inverted front-fork overhaul and oil-level adjustment, Uni-Trak rear-shock disassembly and oil changes, and linkage bearing service.

• Brakes and steering: Caliper and master-cylinder rebuilding, brake-line bleeding, steering adjustment, and steering-stem bearing removal and installation.

• Electrical diagnosis: CDI ignition checks, magneto and crankshaft-sensor testing, plus KX250 throttle-sensor and fuel-cut-valve diagnostics.

Written primarily for trained mechanics in a properly equipped shop, the manual also supports owners doing basic maintenance and repair who understand mechanical work, tools, and workshop procedures.

KIPS, Cylinder and Bottom-End Repair

Top-end specifications cover the chrome composite plating cylinder, piston-to-cylinder clearance, ring wear and compression diagnosis. The cylinder inspection section identifies the limits of this plated design, including its unsuitability for boring or honing.

KIPS documentation distinguishes the KX125 valve layout from the KX250 main and sub-exhaust valves. Governor and exhaust-advancer service, valve alignment checks, expansion-chamber removal and muffler-baffle replacement extend the coverage beyond piston replacement. Top-end precautions explain how reused piston-pin snap rings can score the cylinder wall.

Crankshaft removal, connecting-rod inspection and alignment checks accompany crankcase reassembly. Special tools include Crankcase Splitting Tool Assembly 57001-1098 and Crankshaft Jig 57001-1174; crankshaft disassembly and rebuilding require a shop with the necessary precision equipment.

The clutch section adds KX125 release-shaft lever and adjusting-washer selection tables. Transmission references include gear ratios, gear orientation and shift-fork wear limits.

Carburetors and Cooling System Service

Separate carburetor exploded views and jetting tables distinguish the Mikuni TMX38χ from the Keihin PWK38S. Float-valve, jet-needle and throttle-valve inspections accompany cleaning and reassembly procedures, with different needle and air-screw specifications for the covered variants.

Cooling-system diagnosis covers pressure loss, radiator-cap relief testing and radiator inspection. Water-pump repair extends to the impeller, shaft, bearings and paired oil seals, with seal orientation shown for reassembly.

Forks, Uni-Trak and Chassis Service

The suspension chapter separates M1 from M2-and-later fork construction, oil-level specifications and internal service procedures. Uni-Trak coverage extends to shock reassembly, nitrogen charging and swingarm, tie-rod and rocker-arm bearings; nitrogen charging is assigned to qualified mechanics.

Brake repair includes seal replacement and caliper-holder inspection. Wheel-bearing, rim-runout, chain/sprocket and steering-stem checks round out the chassis sections.

Ignition Diagnostics and Workshop References

The KX125M and KX250M Wiring Diagrams are backed by an ignition Troubleshooting flowchart, Ignition Timing Adjustment views and Cable, Wire and Hose Routing drawings. The flowchart helps narrow ignition faults through coil, crankshaft-sensor and exciter-coil tests before replacing the CDI unit.

Electrical specifications distinguish KX125M6F ignition-coil data and KX125M7F crankshaft-sensor air gaps. KX250-specific tests cover the regulator/rectifier, throttle-sensor input/output voltage and position adjustment, and fuel-cut-valve operation.

Test-equipment cautions explain how unsuitable resistance testers can damage the KX250 regulator/rectifier.

Race-based maintenance charts and component-specific torque tables sit alongside fluid capacities and wear limits. A metric-to-imperial Unit Conversion Table complements the appendix's symptom-based Troubleshooting Guide.

Follow Kawasaki's safety precautions and torque requirements when servicing brakes or engine components.

Printable PDF and Included Pages

The manual comes as one printable 340-page PDF in English. Its total includes 310 technical chapter pages, a 17-page appendix, three introductory/reference pages, one cover, the one-page Model Application table and eight blank pages.