Specs compared
KTM 125 SX 2027 vs Yamaha YZ125 2027
Motocross, stock specs side by side. Each value names the page it came from; a blank on either side stays blank.
Printed differently: stock gearing, fork travel, shock travel, premix ratio, coolant capacity, seat height and weight. The same on both: engine, chain pitch, front tire and rear tire. Checked 28 Sep 2026 and 16 Oct 2026.
| Spec | KTM 125 SX 2027 | Yamaha YZ125 2027 |
|---|---|---|
| EngineSame | 125cc 2T | 125cc 2T |
| Stock gearingPrinted differently | 13T / 50TOwner's manual p. 146 | 13T / 49TOwner's manual p. 2-3 |
| Final drive ratio | 3.85 : 1Calculated from the stock sprockets | 3.769 : 1Owner's manual p. 2-3 |
| Chain pitchSame | 520Owner's manual p. 146 | 520Owner's manual p. 2-7 |
| Front tireSame | 80/100-21 TTOwner's manual p. 146 | 80/100-21 51MOwner's manual p. 2-5 |
| Rear tireSame | 100/90-19 TTOwner's manual p. 146 | 100/90-19 57MOwner's manual p. 2-5 |
| Fork travelPrinted differently | 310 mm (12.2 in)Owner's manual p. 145 | 300 mm (11.8 in)Owner's manual p. 2-6 |
| Shock travelPrinted differently | 300 mm (11.8 in)Owner's manual p. 145 | 315 mm (12.4 in)Owner's manual p. 2-6 |
| Premix ratioPrinted differently | 40:1Owner's manual p. 146 | 30:1Owner's manual p. 2-2 |
| Coolant capacityPrinted differently | 1200 ml (40.6 fl oz)Owner's manual p. 145 | 930 ml (31.4 fl oz)Owner's manual p. 2-2 |
| Seat heightPrinted differently | 958 mm (37.7 in)Owner's manual p. 146 | 980 mm (38.6 in)Owner's manual p. 2-1 |
| WeightPrinted differently | 92 kg (203 lb)Owner's manual p. 146 | 96 kg (212 lb)Owner's manual p. 2-1 |
Each value shows where it came from. The bike pages list the document, page and date checked. “Printed differently” only says the two documents print different figures; it is not a judgement of either bike.
Stock sizes at MotoSport. KTM 125 SX: 520 chains · Front tires 80/100-21 · Rear tires 100/90-19. Yamaha YZ125: 520 chains · Front tires 80/100-21 · Rear tires 100/90-19. These are affiliate links: we may earn a commission, at no cost to you, and it never changes the specs. Affiliate disclosure.