FEATURES
1-5
EASB291015
FI SYSTEM
The fuel pump delivers fuel to the fuel injector via the fuel filter. The pressure regulator maintains the
fuel pressure that is applied to the fuel injector at only 324 kPa (3.24 kgf/cm
2
, 47.0 psi). Accordingly,
when the energizing signal from the ECU energizes the fuel injector, the fuel passage opens, causing
the fuel to be injected into the intake manifold only during the time the passage remains open. There-
fore, the longer the length of time the fuel injector is energized (injection duration), the greater the
volume of fuel that is supplied. Conversely, the shorter the length of time the fuel injector is energized
(injection duration), the lesser the volume of fuel that is supplied.
The injection duration and the injection timing are controlled by the ECU. Signals input from the throt-
tle position sensor, the coolant temperature sensor, the crankshaft position sensor, the intake air
pressure sensor, and the intake air temperature sensor enable the ECU to determine the injection
duration. The injection timing is determined through the signals from the crankshaft position sensor.
As a result, the volume of fuel that is required by the engine can be supplied at all times in accordance
with the driving conditions.
1. Fuel pump
2. Fuel injector
3. ECU
4. Throttle position sensor
5. Coolant temperature sensor
6. Crankshaft position sensor
7. Intake air pressure sensor
8. Throttle body
9. Intake air temperature sensor
10.Air filter case
A. Fuel system
B. Intake system
C. Control system
1
2
3
5
6
7
8
9
10
A
B
C
4
Summary of Contents for YZ 2015 Series
Page 6: ...EASB291006 YAMAHA MOTOR CORPORATION U S A YZ MOTORCYCLE LIMITED WARRANTY...
Page 10: ......
Page 33: ...CONTROL FUNCTIONS 1 21 a 2...
Page 65: ...LUBRICATION POINTS AND LUBRICANT TYPES 2 22 EASB291066...
Page 68: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 25...
Page 70: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 27...
Page 72: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 29...
Page 74: ...CABLE ROUTING DIAGRAM 2 31 EASB291068 CABLE ROUTING DIAGRAM...
Page 76: ...CABLE ROUTING DIAGRAM 2 33...
Page 78: ...CABLE ROUTING DIAGRAM 2 35...
Page 80: ...CABLE ROUTING DIAGRAM 2 37...
Page 82: ...CABLE ROUTING DIAGRAM 2 39...
Page 84: ...CABLE ROUTING DIAGRAM 2 41...
Page 86: ...CABLE ROUTING DIAGRAM 2 43...
Page 88: ...CABLE ROUTING DIAGRAM 2 45...
Page 128: ...ELECTRICAL SYSTEM 3 38...
Page 200: ...CHAIN DRIVE 4 70...
Page 244: ...ELECTRIC STARTER 5 41...
Page 266: ...OIL PUMP AND BALANCER GEAR 5 63 c d 6 6 7 8 8 b...
Page 286: ...TRANSMISSION 5 83...
Page 306: ...CHECKING THE INTAKE AIR TEMPERATURE SENSOR 8 67 CHECKING THE FUEL INJECTOR 8 68...
Page 321: ...CHARGING SYSTEM 8 15 EASB291338...
Page 325: ...COOLING SYSTEM For JPN 8 19 EASB291341...
Page 355: ...FUEL PUMP SYSTEM 8 49 EASB291348...
Page 356: ...ELECTRICAL COMPONENTS 8 50 ELECTRICAL COMPONENTS EASB291349 8 9 10 1 3 2 4 5 6 7...
Page 358: ...ELECTRICAL COMPONENTS 8 52 11 10 9 2 3 1 6 7 8 4 5...
Page 360: ...ELECTRICAL COMPONENTS 8 54 EASB291350 CHECKING THE SWITCHES 4 1 3 2 E B S E B E B E E B B...
Page 382: ...LIST OF SELF DIAGNOSTIC AND FAIL SAFE ACTIONS 9 7...