Yamaha YZ450F User Manual

ENGINE SPECIFICATIONS
2-7
Shifting mechanism
Shift mechanism type Shift drum and guide bar
Shift fork guide bar bending limit 0.050 mm (0.0020 in)
Shift fork thickness 4.85 mm (0.1909 in)
Decompression device
Device type Auto decomp
Air filter
Air filter element Wet element
Air filter oil grade Foam air-filter oil
Fuel pump
Pump type Electrical
Fuel injector
Model/quantity 1010/1
Resistance 12 
Throttle body
Type/quantity 30RA-JX1A/1
ID mark 1SL5 10
Fuel pressure 324.0 kPa (3.24 kgf/cm
2
, 47.0 psi)
Throttle position sensor
Resistance 6.30 k
Output voltage (at idle) 0.48–0.52 V
Fuel injection sensor
Crankshaft position sensor resistance 248–372 
Intake air pressure sensor output voltage 3.57–3.71 V at 101.3 kPa
Intake air temperature sensor resistance 290–390  at 80 °C (176 °F)
Coolant temperature sensor resistance 2.51–2.78 k at 20°C (68°F)
210–221  at 100°C (212°F)
Idling condition
Engine idling speed 1900–2100 r/min
CO% 6.8–9.2 %
Intake vacuum 30.5–37.8 kPa (229–284 mmHg,
9.0–11.2 inHg)
Water temperature 70–80 °C (158–176 °F)
Oil temperature 55–65 °C (131–149 °F)
Throttle grip free play 3.0–5.0 mm (0.12–0.20 in)

Yamaha YZ450F Specifications

General

Displacement	449cc
Bore x Stroke	97.0 mm x 60.8 mm
Transmission	5-speed
Final Drive	Chain
Width	32.5 in
Seat Height	38.2 in
Wheelbase	58.5 in
Fuel Capacity	1.6 gal
Fuel System	Fuel Injection
Front Suspension	KYB® Speed-Sensitive System inverted fork; fully adjustable, 12.2-in travel
Front Brakes	Hydraulic single disc, 270mm
Rear Brakes	Hydraulic single disc
Front Tire	80/100-21
Rear Tire	120/80-19
Wet Weight	245 lbs
Engine Type	Liquid-cooled, 4-stroke, DOHC, 4-valve