Yamaha YZ450FX 2021 Owner's Service Manual page 49

Clutch spring free length limit
Push rod bending limit
Drivetrain
Primary reduction ratio
Transmission type
Gear ratio
1st
2nd
3rd
4th
5th
Main axle runout limit
Drive axle runout limit
Secondary reduction ratio
Final drive
Air filter
Air filter element
Air filter oil grade
Fuel pump
Pump type
Maximum consumption amperage
Fuel injector
Resistance
Throttle body
ID mark
Idling condition
Engine idling speed
Coolant temperature
Fuel line pressure (at idle)
Throttle grip free play
ENGINE SPECIFICATIONS
45.60 mm (1.80 in)
0.10 mm (0.004 in)
2.609 (60/23)
Constant mesh 5-speed
2.417 (29/12)
1.733 (26/15)
1.313 (21/16)
1.050 (21/20)
0.840 (21/25)
0.08 mm (0.0032 in)
0.08 mm (0.0032 in)
3.846 (50/13)
Chain
Wet element
Yamaha foam air filter oil or other quality foam
air filter oil
Electrical
2.4 A
12.0 
BR91
1900–2100 r/min
70–80 C (158–176 F)
300–390 kPa (3.0–3.9 kgf/cm², 43.5–56.6 psi)
3.0–6.0 mm (0.12–0.24 in)
2-4