1980 Kawasaki KX125 Specifications and Specs
Specifications and workshop reference information for the 1980 Kawasaki KX125, including engine, chassis, service data and setup details.
Note: Specs are compiled from factory data, manuals and owner feedback. Bikes vary — if yours is different, jump into the forum and share it.
General Specifications
| Engine Type | 2-stroke, single-cylinder, piston reed valve |
| Displacement | 124 cc |
| Bore × Stroke | 56.0 × 50.6 mm |
| Compression Ratio | 7.7:1 |
| Maximum Power | 28 HP @ 11,500 rpm |
| Maximum Torque | 1.84 kg-m @ 9,500 rpm (13.3 ft-lb) |
| Carburetor | Mikuni VM34SS | Replacement Options |
| Fuel Type | Petrol mix (20:1) |
| Lubrication | Premix |
| Starting System | Primary kick |
| Ignition | Electronic CDI |
| Ignition Timing | 22° BTDC @ 10,000 rpm (2.18 mm) |
| Spark Plug | NGK B9EV |
| Reed Valve | Boyesen type |
Port Timing
| Inlet Open | — |
| Scavenging Open | 64° BBDC |
| Scavenging Close | 64° ABDC |
| Exhaust Open | 96° BBDC |
| Exhaust Close | 96° ABDC |
Transmission
| Transmission Type | 6-speed constant mesh, return shift |
| Clutch | Wet, multi-disc |
| Final Drive Type | Chain drive |
| 1st Gear | 2.14 (30/14) |
| 2nd Gear | 1.67 (30/18) |
| 3rd Gear | 1.33 (24/18) |
| 4th Gear | 1.15 (23/20) |
| 5th Gear | 1.00 (21/21) |
| 6th Gear | 0.91 (20/22) |
| Primary Reduction | 3.55 (71/20) |
| Final Reduction | 4.42 (53/12) |
| Overall Drive Ratio | 14.25 (Top gear) |
| Transmission Oil Capacity | 0.55 L (0.58 US qt) |
| Transmission Oil Type | SE class SAE 10W30 or 10W40 |
Dimensions
| Overall Length | 2160 mm (85.0 in) |
| Overall Width | 880 mm (34.6 in) |
| Overall Height | 1230 mm (48.4 in) |
| Wheelbase | 1470 mm (57.9 in) |
| Ground Clearance | 330 mm (13.0 in) |
| Dry Weight | 90 kg (198 lb) |
| Fuel Tank Capacity | 8.0 L (2.1 US gal) |
| Bearing Sizes |
Bearing Finder |
Chassis
| Frame Type | Tubular, single down tube |
| Steering Angle | 42° |
| Caster | 28° |
| Trail | 120 mm (4.72 in) |
| Front Tire | 3.00-21 4PR | Tyre Size Guide |
| Rear Tire | 4.00-18 4PR | Tyre Size Guide |
Suspension
| Front | Telescopic fork |
| Rear | Swing arm |
| Front Suspension Travel | 280 mm (11.0 in) |
| Rear Wheel Travel | 280 mm (11.0 in) |
| Fork Oil Type | KYB G-15 or SAE 10W20 |
| Fork Oil Capacity | 432 cc (14.61 US oz) |
Brakes & Wheels
| Front Brake | Drum brake |
| Rear Brake | Drum brake |
| Front Drum Size | 120 × 28 mm (4.7 × 1.1 in) |
| Rear Drum Size | 130 × 28 mm (5.1 × 1.1 in) |
125cc Other Specs
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