2020 KTM 125 SX vs 2021 Yamaha YZ125X
Full specifications comparison •
2 motorcycles
Full Specifications
Differs
Same
| General |
| Colours | White, Orange | Team Yamaha Blue |
| Warranty | - | 30 Day Limited Factory Warranty |
| Dimensions |
| Ground Clearance (in.) | - | 13.8 inches |
| Ground Clearance (mm) | - | 351 mm |
| Seat Height | - | 975 mm / 38.4 in. |
| Wheelbase | - | 1455 mm / 57.3 in. |
| Height | - | 1285 mm / 50.6 in. |
| Length | - | 2141 mm / 84.3 in. |
| Width | - | 825 mm / 32.5 in. |
| Weights & Capacities |
| Oil Capacity (Quarts) | - | 0.74 US quarts |
| Oil Capacity (l) | - | 0.70 litres |
| Dry Weight | 137 kg / 302.0 lbs | - |
| Fuel Capacity | - | 8.00 litres / 2.11 US gallons |
| Wet Weight | - | 94.8 kg / 209.0 lbs |
| Performance |
| Power-to-Weight Ratio | 0.1095 HP/kg | - |
| Engine |
| Fuel Control | Double Overhead Cams/Twin Cam (DOHC) | - |
| Engine Type | Single cylinder, two-stroke | Single cylinder, two-stroke |
| Displacement (ci) | 7.62 cubic inches | 7.63 cubic inches |
| Displacement (cc) | 124.8 cc | 125.0 cc |
| Bore x Stroke (mm) | 54.0 x 54.5 mm | 54.0 x 54.5 mm |
| Bore x Stroke (in,) | 2.1 x 2.1 inches | 2.1 x 2.1 inches |
| Engine Detail | - | Reed-valve-inducted |
| Fuel System | Injection | Carburettor. Mikuni TMX 38 |
| Compression Ratio | - | 8.8:1 |
| Engine Lubrication | Wet sump | Premix |
| Ignition | Contactless, controlled, fully electronic ignition system with digital ignition timing adjustment, type Kokusan | CDI |
| Starter | Electric | Kick |
| Drivetrain |
| Clutch | Wet multi-disc clutch, mechanically actuated | O-ring chain |
| Final Drive | Chain (final drive) | Chain (final drive) |
| Gearbox | 6-speed | 6-speed |
| Primary Drive | 5/8 x 1/4 (520) O Ring. Primary drive: 22:72. | - |
| Chassis |
| Frame Type | Central double-cradle | Semi-double cradle aluminium frame |
| Suspension - Front | WP upside-down Ø 48 mm | KYB® Speed-Sensitive System inverted fork; fully adjustable |
| Suspension - Rear | WP Monoshock | KYB® single shock; fully adjustable |
| Rake | - | 26.8° |
| Trail | - | 117 mm / 4.6 in. |
| Wheel Travel - Front | - | 300 mm / 11.8 in. |
| Wheel Travel - Rear | 150 mm / 5.9 in. | 315 mm / 12.4 in. |
| Wheels & Brakes |
| Brakes - Front | Single disc | Single disc. Hydraulic. |
| Brakes - Rear | Single disc | Single disc. Hydraulic. |
| Rims | - | Dunlop® AT81 tires |
| Tyres - Front | 110-17 | 90/90-21 |
Verdict
⚖️
Too close to call
The 2020 KTM 125 SX and the 2021 Yamaha YZ125X are evenly matched across the key measurable criteria. Your decision comes down to personal preference, riding style, and which brand's dealer network best suits your location.
Key Differences
2020 KTM 125 SX - Advantages
- 🔧Fuel injection: Precise fuelling, better cold-start reliability, and lower maintenance requirements.
2021 Yamaha YZ125X - Advantages
- 🔄More rear wheel travel: 315 mm vs 150 mm - absorbs bigger hits and rough terrain better.
2020 KTM 125 SX vs 2021 Yamaha YZ125X - FAQs
Which should I buy, the 2020 KTM 125 SX or the 2021 Yamaha YZ125X?
Both are strong choices. The 2020 KTM 125 SX has the edge in fuel injection, while the 2021 Yamaha YZ125X stands out for higher rear wheel travel. Visit dealers, arrange test rides, and factor in local parts and service costs - these often matter as much as the spec sheet.