1987 KX250 Manual

The 1987 Kawasaki KX250 is a high-performance motocross motorcycle featuring a 249cc liquid-cooled two-stroke engine, Uni-Trak rear suspension system, front and rear disc brakes, and competition-oriented chassis design. This manual covers maintenance procedures, specifications, troubleshooting, and repair guidelines for optimal performance and longevity.

1. Specifications 2. Maintenance Schedule 3. Engine Service 4. Chassis & Suspension 5. Electrical System 6. Brake System 7. Fuel System 8. Troubleshooting 9. Torque Specifications 10. Safety Information

Specifications

Technical specifications for the 1987 Kawasaki KX250 motocross motorcycle.

Component	Specification
Engine Type	249cc liquid-cooled two-stroke single
Bore x Stroke	67.0 x 70.8mm
Compression Ratio	8.4:1
Carburetor	Keihin PWK 38mm
Ignition	CDI electronic ignition
Transmission	5-speed constant mesh
Front Suspension	Air-adjustable telescopic fork
Rear Suspension	Uni-Trak system with adjustable preload
Front Brake	Single disc, 240mm
Rear Brake	Single disc, 240mm
Dry Weight	102 kg (225 lbs)
Fuel Capacity	9.5 liters (2.5 gallons)

Maintenance Schedule

Regular maintenance intervals for optimal performance and reliability.

Before each ride: Check tire pressure, brake function, chain tension.
After each ride: Clean air filter, check for loose fasteners.
Every 10 hours: Change transmission oil, inspect spark plug.
Every 20 hours: Clean carburetor, check wheel bearings.
Every 50 hours: Top end inspection, suspension service.
Annually: Complete engine overhaul inspection.

WARNING! Always perform maintenance with engine off and cool. Use proper safety equipment.

Engine Service

Engine maintenance and repair procedures.

Top end rebuild: Remove cylinder head, inspect piston and rings.
Carburetor adjustment: Main jet 162, pilot jet 52, needle clip position 3.
Ignition timing: Set to 1.8mm BTDC at 5000 RPM.
Cooling system: Check radiator fluid level, inspect hoses for leaks.
Transmission: Use 10W-40 motorcycle oil, capacity 750ml.

CAUTION! Engine components become extremely hot during operation. Allow to cool before servicing.

Chassis & Suspension

Frame: High-tensile steel perimeter design.
Front Fork: 43mm conventional, air pressure 0-6 psi.
Rear Shock: Kayaba with adjustable rebound and compression.
Wheelbase: 1490mm (58.7 inches).
Ground Clearance: 370mm (14.6 inches).
Seat Height: 955mm (37.6 inches).

Electrical System

CDI ignition system with lighting coil. Battery not required for ignition operation.

Components: CDI unit, ignition coil, spark plug (NGK BR8ES), stator assembly.

Testing procedures: Check spark plug gap (0.6-0.7mm), ignition coil resistance (primary 0.1-0.3Ω, secondary 4.5-6.5kΩ), stator output (30-50V AC at 3000 RPM).

Brake System

Hydraulic disc brakes front and rear with sintered metal pads.

Front brake: Single piston caliper, 240mm rotor.
Rear brake: Single piston caliper, 240mm rotor.
Brake fluid: DOT 4, change every 2 years.
Pad replacement: Inspect when thickness below 1.5mm.

Tip: Bleed brakes after pad replacement to remove air from system.

Fuel System

Keihin PWK 38mm carburetor with throttle position sensor.

Fuel mixture: 32:1 premium unleaded with 2-stroke oil.
Float height: 16mm ± 1mm.
Idle speed: 1300 ± 100 RPM.
Air screw: 1.5 turns out from lightly seated.
Fuel filter: Clean every 20 hours of operation.

WARNING! Gasoline is highly flammable. No smoking during fuel system service.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Hard starting	Fouled spark plug, stale fuel	Replace spark plug, drain old fuel, clean carburetor.
Poor performance	Clogged air filter, incorrect jetting	Clean air filter, check carburetor settings.
Overheating	Lean mixture, low coolant	Check jetting, refill coolant system.
Transmission issues	Worn clutch, incorrect oil	Inspect clutch plates, change transmission oil.
Brake fade	Contaminated pads, old fluid	Replace pads, bleed brake system.

Torque Specifications

Critical fastener torque values for proper assembly.

Component	Torque Value
Cylinder head nuts	22 Nm (16 ft-lbs)
Spark plug	12 Nm (9 ft-lbs)
Front axle nut	65 Nm (47 ft-lbs)
Rear axle nut	105 Nm (76 ft-lbs)
Clutch spring bolts	10 Nm (7 ft-lbs)
Wheel spokes	4 Nm (3 ft-lbs)

Safety Information

Always wear approved helmet, eye protection, and protective clothing. This motorcycle is designed for off-road competition use only. Not intended for public roads. Kawasaki recommends professional training before operation. Regular maintenance is essential for safe operation.

CAUTION! High-performance motorcycle requires skilled operator. Never operate under influence of drugs or alcohol.