The 1986 Kawasaki KX 125 is a high-performance motocross motorcycle featuring a liquid-cooled 2-stroke 125cc engine, 6-speed transmission, Uni-Trak rear suspension, and advanced chassis design for competitive racing. Below are key sections covering specifications, maintenance procedures, troubleshooting, and technical data.
Complete technical specifications for the 1986 Kawasaki KX 125 motocross bike.
| Component | Specification |
|---|---|
| Engine Type | Liquid-cooled 2-stroke single |
| Displacement | 124cc |
| Bore x Stroke | 56.0 x 50.5mm |
| Compression Ratio | 8.4:1 |
| Carburetor | Keihin PE28 |
| Ignition | CDI electronic |
| Transmission | 6-speed constant mesh |
| Final Drive | 520 chain |
| Suspension Front | Air-adjustable telescopic fork |
| Suspension Rear | Uni-Trak swingarm |
| Brakes Front | Single disc |
| Brakes Rear | Single drum |
| Dry Weight | 91 kg (201 lbs) |
| Fuel Capacity | 7.5 liters (2.0 gal) |
Proper maintenance procedures for the 2-stroke engine.
WARNING! Always allow engine to cool before maintenance. Use proper safety equipment.
Frame geometry and suspension adjustment procedures.
Adjustment Tip: Set sag to 95-100mm for optimal handling.
Complete electrical specifications and maintenance.
| Component | Specification |
|---|---|
| Ignition Timing | 1.8mm BTDC (fixed) |
| Spark Advance | Electronic CDI controlled |
| Lighting Coil | 30W AC output |
| Battery | Not applicable (magneto ignition) |
| Bulb Headlight | 35W/35W (if equipped) |
Standard carburetor jetting and adjustment specifications.
Note: Jetting may vary based on altitude and temperature conditions.
Gear ratios and clutch specifications.
Brake specifications and maintenance procedures.
CAUTION! Always replace brake pads in sets. Check fluid regularly.
Recommended service intervals for optimal performance.
| Service Item | Every Race | Every 3 Races | Every Season |
|---|---|---|---|
| Air Filter Clean | ✓ | ||
| Transmission Oil | ✓ | ||
| Coolant Change | ✓ | ||
| Piston Replacement | ✓ | ||
| Wheel Bearing Check | ✓ | ||
| Swingarm Bearing | ✓ | ||
| Brake Inspection | ✓ | ||
| Chain Adjustment | ✓ |
Common issues and solutions for the KX 125.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| Hard starting | Fouled plug, stale fuel | Replace spark plug, drain old fuel mixture |
| Poor top end power | Clogged main jet, worn piston | Clean carburetor, inspect piston and rings |
| Transmission slipping | Worn clutch plates | Replace clutch plates and springs |
| Overheating | Low coolant, stuck thermostat | Check coolant level, inspect cooling system |
| Poor suspension | Worn bushings, low oil | Replace suspension linkage, change fork oil |
| Brake fade | Contaminated pads, old fluid | Replace brake pads, flush brake system |
Genuine Kawasaki parts and recommended aftermarket components.
Reference diagrams available in the complete manual PDF.
Exploded views included for: - Complete engine assembly - Transmission components - Carburetor breakdown - Electrical system routing - Frame and suspension - Brake system components
Note: Full technical drawings with part numbers available in downloadable PDF.