By model year

Yamaha YZ250
2015 vs 2027

2 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

4 different10 the same0 printed differently9 not compared

Different on the manual pages

The records are for different markets (2015: not stated; 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.

Yamaha YZ250 stock specs by model year, each value with its source, and whether the manual pages agree
SpecManual pages20152027
Stock front sprocketSame on the manuals14TOwner's manual p. 2-214TOwner's manual p. 2-3
Stock rear sprocketSame on the manuals50TOwner's manual p. 2-250TOwner's manual p. 2-3
Chain pitchSame on the manuals520Owner's manual p. 2-6520Owner's manual p. 2-7
Stock final drive ratioNot comparedBlank in a record Not yet verified3.571 : 1Owner's manual p. 2-3
Front rimNot comparedBlank in a record Not yet verified21x1.6Owner's manual p. 2-5
Rear rimNot comparedBlank in a record Not yet verified19x2.15Owner's manual p. 2-5
Front tireSame on the manuals80/100-21 51MOwner's manual p. 2-280/100-21 51MOwner's manual p. 2-5
Rear tireSame on the manuals110/90-19 62MOwner's manual p. 2-2110/90-19 62MOwner's manual p. 2-5
ForkNot comparedBlank in a record Not yet verifiedTelescopic fork, coil springOwner's manual p. 2-5
Fork travelSame on the manuals300 mm (11.8 in)Owner's manual p. 2-2300 mm (11.8 in)Owner's manual p. 2-6
Shock travelSame on the manuals315 mm (12.4 in)Owner's manual p. 2-2315 mm (12.4 in)Owner's manual p. 2-6
Stock fork spring rateNot comparedBlank in a record Not yet verified4.4 N/mmOwner's manual p. 10-12
Stock shock spring rateNot comparedBlank in a record Not yet verified50 N/mmOwner's manual p. 10-13
Coolant capacityDifferent on the manuals1200 ml (40.6 fl oz)Owner's manual p. 2-11180 ml (39.9 fl oz)Owner's manual p. 2-2
Premix ratioNot comparedBlank in a record Not yet verified30:1Owner's manual p. 2-2
Fuel capacityDifferent on the manuals8 L (2.11 gal)Owner's manual p. 2-17 L (1.85 gal)Owner's manual p. 2-2
Tire pressure (off-road)Same on the manuals100 kPa (15 psi) front and rearOwner's manual p. 2-2100 kPa (15 psi) front and rearOwner's manual p. 2-5
Chain slackNot comparedBlank in a record Not yet verified48-58 mm (1.89-2.28 in), on a maintenance standOwner's manual p. 2-7
Spark plug and gapSame on the manualsNGK BR8EG, gap 0.5-0.6 mmOwner's manual p. 2-1NGK BR8EG, gap 0.5-0.6 mmOwner's manual p. 2-2
Seat heightDifferent on the manuals976 mm (38.4 in)Owner's manual p. 2-1975 mm (38.4 in)Owner's manual p. 2-1
WheelbaseDifferent on the manuals1446 mm (56.9 in)Owner's manual p. 2-11485 mm (58.5 in)Owner's manual p. 2-1
WeightSame on the manuals103 kg (227 lb)Owner's manual p. 2-1103 kg (227 lb)Owner's manual p. 2-1