1987 Kawasaki KX125 Manual

The 1987 Kawasaki KX125 is a high-performance motocross motorcycle featuring a liquid-cooled 2-stroke 125cc engine, 6-speed transmission, Uni-Trak rear suspension system, and advanced chassis design for competitive racing. Below are key sections covering specifications, maintenance procedures, troubleshooting, and operational guidelines.

1. Specifications 2. Engine System 3. Chassis & Suspension 4. Maintenance Schedule 5. Troubleshooting 6. Carburetor Adjustment 7. Electrical System 8. Brake System 9. Safety Precautions 10. Warranty Information

Specifications

Technical specifications for the 1987 Kawasaki KX125 motocross motorcycle.

ComponentSpecification
Engine TypeLiquid-cooled 2-stroke single cylinder
Displacement124cc
Bore x Stroke54.0 x 54.4mm
Compression Ratio8.4:1
CarburetorKeihin PE34
Transmission6-speed constant mesh
Final Drive520 chain
Suspension FrontAir-adjustable telescopic fork
Suspension RearUni-Trak system with adjustable preload
Brakes FrontSingle disc
Brakes RearSingle drum
Fuel Capacity2.1 gallons (8 liters)
Dry Weight194 lbs (88 kg)

Engine System

Detailed information about the 2-stroke engine components and maintenance procedures.

  1. Cylinder and Piston: Nikasil-plated cylinder with forged piston
  2. Ignition System: CDI electronic ignition
  3. Lubrication: Pre-mix fuel/oil system (32:1 ratio recommended)
  4. Cooling System: Liquid-cooled with radiator and water pump
  5. Exhaust System: Expansion chamber with silencer

WARNING! Always use proper 2-stroke oil mixture to prevent engine damage.

Chassis & Suspension

Frame and suspension components with adjustment procedures.

  1. Frame: Semi-double cradle steel frame
  2. Front Suspension: 41mm telescopic fork, 11.8 inches travel
  3. Rear Suspension: Uni-Trak system, 12.2 inches travel
  4. Wheels: Front 21-inch, Rear 19-inch with knobby tires
  5. Ground Clearance: 13.4 inches

CAUTION! Check suspension settings before each ride for optimal performance.

Maintenance Schedule

Recommended maintenance intervals for optimal performance.

Troubleshooting

Common issues and solutions for the KX125.

SymptomPossible CauseCorrective Action
Hard startingFouled spark plug, improper fuel mixtureReplace spark plug, check fuel/oil ratio
Poor performanceClogged air filter, carburetor issuesClean air filter, adjust carburetor jets
OverheatingLow coolant, radiator blockageCheck coolant level, clean radiator fins
Transmission issuesWorn clutch, improper oil levelInspect clutch plates, change transmission oil
Brake problemsWorn pads, air in linesReplace brake pads, bleed brake system

Carburetor Adjustment

Keihin PE34 carburetor settings and adjustment procedures.

  1. Main Jet: #160 (standard setting)
  2. Pilot Jet: #55 (standard setting)
  3. Needle: 6F21-3 (middle clip position)
  4. Air Screw: 1.5 turns out
  5. Float Height: 16.5mm

Tip: Adjust jetting based on altitude and temperature conditions.

Electrical System

CDI ignition and lighting system components.

Brake System

Front disc and rear drum brake maintenance.

  1. Front Brake: Single piston caliper, disc brake
  2. Rear Brake: Mechanical drum brake
  3. Brake Fluid: DOT 4 (front brake system)
  4. Pad Replacement: Replace when thickness below 1mm
  5. Adjustment: Rear brake cable adjustment at lever

WARNING! Test brakes before each ride and replace worn components immediately.

Safety Precautions

Important safety information for operation and maintenance.

CAUTION! This is a competition vehicle - not designed for street use.

Warranty Information

Limited warranty coverage and dealer network information.

Kawasaki Motors Corp., U.S.A. provides a 30-day limited warranty for competition use. Warranty covers manufacturing defects in materials and workmanship. Normal maintenance items, wear items, and damage from racing are not covered. For warranty claims, contact your authorized Kawasaki dealer with proof of purchase.

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