By model year
Yamaha YZ125
2016 to 2027
4 model-year records side by side. A row is compared only where manual pages print the value; spec-sheet figures are shown but not judged.
On the manual pages
9 different11 the same4 printed differently4 not compared
Different on the manual pages
- Stock rear sprocket
- Front rim
- Coolant capacity
- Fuel capacity
- Gearbox oil
- Fork oil
- Brake fluid
- Seat height
- Weight
The records are for different markets (2016: not stated; 2025: US version; 2026: US version; 2027: EU/AU identical). Figures can differ between markets, not only between years.
"Not compared" means fewer than two records have the value from a manual page; it says nothing about whether the bike changed. "Printed differently" marks descriptions (the fork, the oil, pressures with printed conversions) that the manuals word differently; read both before assuming a change.
| Spec | Manual pages | 2016 | 2025 | 2026 | 2027 |
|---|---|---|---|---|---|
| Stock front sprocket | Same on the manuals | 13TOwner's manual p. 2-2 | 13TOwner's manual p. 2-3 | 13TOwner's manual p. 2-3 | 13TOwner's manual p. 2-3 |
| Stock rear sprocket | Different on the manuals | 48TOwner's manual p. 2-2 | 49TOwner's manual p. 2-3 | 49TOwner's manual p. 2-3 | 49TOwner's manual p. 2-3 |
| Chain pitch | Same on the manuals | 520Owner's manual p. 2-7 | 520Owner's manual p. 2-7 | 520Owner's manual p. 2-7 | 520Owner's manual p. 2-7 |
| Stock chain links | Same on the manuals | Not yet verified | 112Owner's manual p. 2-7 | 112Owner's manual p. 2-7 | 112Owner's manual p. 2-7 |
| Stock final drive ratio | Same on the manuals | Not yet verified | 3.769 : 1Owner's manual p. 2-3 | 3.769 : 1Owner's manual p. 2-3 | 3.769 : 1Owner's manual p. 2-3 |
| Front rim | Different on the manuals | Not yet verified | 21 x 1.60Owner's manual p. 2-5 | 21 x 1.60Owner's manual p. 2-5 | 21x1.6Owner's manual p. 2-5 |
| Rear rim | Same on the manuals | Not yet verified | 19 x 1.85Owner's manual p. 2-5 | 19 x 1.85Owner's manual p. 2-5 | 19x1.85Owner's manual p. 2-5 |
| Front tire | Same on the manuals | 80/100-21 51MOwner's manual p. 2-2 | 80/100-21 51MOwner's manual p. 2-5 | 80/100-21 51MOwner's manual p. 2-5 | 80/100-21 51MOwner's manual p. 2-5 |
| Rear tire | Same on the manuals | 100/90-19 57MOwner's manual p. 2-2 | 100/90-19 57MOwner's manual p. 2-5 | 100/90-19 57MOwner's manual p. 2-5 | 100/90-19 57MOwner's manual p. 2-5 |
| Fork | Printed differently | Not yet verified | Telescopic forkOwner's manual p. 2-5 | Telescopic forkOwner's manual p. 2-5 | Telescopic fork, coil springOwner's manual p. 2-5 |
| Fork travel | Same on the manuals | 300 mm (11.8 in)Owner's manual p. 2-2 | 300 mm (11.8 in)Owner's manual p. 2-6 | 300 mm (11.8 in)Owner's manual p. 2-6 | 300 mm (11.8 in)Owner's manual p. 2-6 |
| Shock travel | Same on the manuals | 315 mm (12.4 in)Owner's manual p. 2-2 | 315 mm (12.4 in)Owner's manual p. 2-6 | 315 mm (12.4 in)Owner's manual p. 2-6 | 315 mm (12.4 in)Owner's manual p. 2-6 |
| Stock fork spring rate | Not comparedBlank in a record | Not yet verified | Not yet verified | Not yet verified | 4.2 N/mmOwner's manual p. 10-12 |
| Stock shock spring rate | Not comparedBlank in a record | Not yet verified | Not yet verified | Not yet verified | 48 N/mmOwner's manual p. 10-13 |
| Coolant capacity | Different on the manuals | 900 ml (30.4 fl oz)Owner's manual p. 2-1 | 930 ml (31.4 fl oz)Owner's manual p. 2-2 | 930 ml (31.4 fl oz)Owner's manual p. 2-2 | 930 ml (31.4 fl oz)Owner's manual p. 2-2 |
| Premix ratio | Same on the manuals | Not yet verified | 30:1Owner's manual p. 2-2 | 30:1Owner's manual p. 2-2 | 30:1Owner's manual p. 2-2 |
| Fuel capacity | Different on the manuals | 8 L (2.11 gal)Owner's manual p. 2-1 | 7 L (1.85 gal)Owner's manual p. 2-2 | 7 L (1.85 gal)Owner's manual p. 2-2 | 7 L (1.85 gal)Owner's manual p. 2-2 |
| Gearbox oil | Different on the manuals | Recommended brand: YAMALUBE SAE10W-40 API service SG type or higher, JASO standard MA; Periodic oil change 0.66 L (0.58 Imp qt, 0.70 US qt); Total amount 0.70 L (0.62 Imp qt, 0.74 US qt)Owner's manual p. 2-1 | Motor oil SAE 10W-40 type SG or higher; Quantity (disassembled) 0.76 L (0.80 US qt, 0.67 Imp.qt); Quantity 0.70 L (0.74 US qt, 0.62 Imp.qt)Owner's manual p. 2-2 | Motor oil SAE 10W-40 type SG or higher; Quantity (disassembled) 0.76 L (0.80 US qt, 0.67 Imp.qt); Quantity 0.70 L (0.74 US qt, 0.62 Imp.qt)Owner's manual p. 2-2 | Not yet verified |
| Fork oil | Different on the manuals | Oil capacity 510.0 cm3 (17.99 Imp oz, 17.24 US oz); Oil grade Suspension oil "S1"Owner's manual p. 2-6 | Yamaha Suspension Oil S1; Quantity (left) 500.0 cm³ (16.91 US oz, 17.64 Imp.oz); Quantity (right) 500.0 cm³ (16.91 US oz, 17.64 Imp.oz)Owner's manual p. 2-6 | Yamaha Suspension Oil S1; Quantity (left) 500.0 cm³ (16.91 US oz, 17.64 Imp.oz); Quantity (right) 500.0 cm³ (16.91 US oz, 17.64 Imp.oz)Owner's manual p. 2-6 | Not yet verified |
| Brake fluid | Different on the manuals | DOT #4Owner's manual p. 2-7 | DOT 4Owner's manual p. 2-5 | DOT 4Owner's manual p. 2-5 | Not yet verified |
| Coolant type | Not comparedBlank in a record | High quality ethylene glycol antifreeze containing anti-corrosion for aluminum engineOwner's manual p. 3-6 | Not yet verified | Not yet verified | Not yet verified |
| Fuel octane | Not comparedBlank in a record | Premium unleaded gasoline only with a research octane number of 95 or higherOwner's manual p. 2-1 | Not yet verified | Not yet verified | Not yet verified |
| Tire pressure (off-road) | Printed differently | 100 kPa (15 psi) front and rearOwner's manual p. 2-2 | 100 kPa (1.00 kgf/cm², 15 psi) front and rear, measured on cold tiresOwner's manual p. 2-5 | 100 kPa (1.00 kgf/cm², 15 psi) front and rear, measured on cold tiresOwner's manual p. 2-5 | 100 kPa (15 psi) front and rearOwner's manual p. 2-5 |
| Chain slack | Printed differently | Not yet verified | 48.0–58.0 mm (1.89–2.28 in), on a maintenance standOwner's manual p. 2-7 | 48.0–58.0 mm (1.89–2.28 in), on a maintenance standOwner's manual p. 2-7 | 48-58 mm (1.89-2.28 in), on a maintenance standOwner's manual p. 2-7 |
| Spark plug and gap | Printed differently | NGK BR9EVX, gap 0.6-0.7 mmOwner's manual p. 2-1 | NGK/BR9EVX, gap 0.6–0.7 mm (0.024–0.028 in)Owner's manual p. 2-2 | NGK/BR9EVX, gap 0.6–0.7 mm (0.024–0.028 in)Owner's manual p. 2-2 | NGK BR9EVX, gap 0.6-0.7 mmOwner's manual p. 2-2 |
| Seat height | Different on the manuals | 975 mm (38.4 in)Owner's manual p. 2-1 | 980 mm (38.6 in)Owner's manual p. 2-1 | 980 mm (38.6 in)Owner's manual p. 2-1 | 980 mm (38.6 in)Owner's manual p. 2-1 |
| Wheelbase | Same on the manuals | 1445 mm (56.9 in)Owner's manual p. 2-1 | 1445 mm (56.9 in)Owner's manual p. 2-1 | 1445 mm (56.9 in)Owner's manual p. 2-1 | 1445 mm (56.9 in)Owner's manual p. 2-1 |
| Weight | Different on the manuals | 94 kg (207 lb)Owner's manual p. 2-1 | 96 kg (212 lb)Owner's manual p. 2-1 | 96 kg (212 lb)Owner's manual p. 2-1 | 96 kg (212 lb)Owner's manual p. 2-1 |