Yamaha Fz6n Manual

7-28
THROTTLE BODIESFI
CAUTION:
CAUTION:
EAS00911
The throttle bodies should not be disas-
sembled.
EAS00912
CHECKING THE INJECTORS
1. Check:

injectors
Damage 
 Replace.
EAS00913
CHECKING THE THROTTLE BODIES
1. Check:

throttle bodies
Cracks / damage 
 Replace the throttle bo-
dies as a set.
2. Check:

fuel passages
Obstructions 
 Clean.
a. Wash the throttle bodies in a petroleum-
based solvent.
Do not use any caustic carburetor cleaning
solution.
b. Blow out all of the passages with com-
pressed air....

7-29
THROTTLE BODIESFI
CHECKING THE FUEL PUMP AND 
PRESSURE REGULATOR OPERATION
1. Check:

fuel pump operation
Refer to “FUEL TANK” in chapter 3.
a. Remove the seat fuel tank.
Refer to “SEAT AND FUEL TANK” in chapter
3.
b. Connect the pressure gauge 
1 and adapter
2 onto the fuel injection pipe.
Pressure gauge
90890-03153, YU-03153
Adapter
90890-03176, YM-03176
c. Install the fuel tank.
Refer to “FUEL TANK” in chapter 3.
d. Start the engine.
e. Measure the fuel pressure.
Fuel pressure
250 kPa (2.5 kg /...

7-30
THROTTLE BODIESFI
NOTE:
EAS00916
CHECKING AND ADJUSTING THE 
THROTTLE POSITION SENSOR
Before adjusting the throttle position sensor, the
engine idling speed should be properly ad-
justed.
1. Check:

throttle position sensor
a. Disconnect the throttle position sensor cou-
pler.
b. Remove the throttle position sensor from the
throttle body.
c. Connect the pocket tester (Ω  1k) to the
throttle position sensor.
Positive tester probe 
 blue terminal 
1
Negative tester probe 
black / blue
terminal 
2
d....

7-31
THROTTLE BODIESFI
NOTE:
Tester positive probe 
 yellow terminal 
Tester negative probe 

black / blue terminal 1
2
f. While slowly opening the throttle, check that
the throttle position sensor resistance is with-
in the specified range.
The resistance does not change or it
changes abruptly 
Replace the throttle
position sensor.
The slot is worn or broken  
 Replace the
throttle position sensor.
Check mainly that the resistance changes grad-
ually when turning the throttle, since the read-
ings (from...

7-32
AIR INDUCTION SYSTEMFI
EAS00507
AIR INDUCTION SYSTEM
AIR INJECTION
The air induction system burns unburned ex-
haust gases by injecting fresh air (secondary
air) into the exhaust port, reducing the emission
of hydrocarbons.
When there is negative pressure at the exhaust
port, the reed valve opens, allowing secondary
air to flow into the exhaust port. The required
temperature for burning the unburned exhaust
gases is approximately 600 to 700C (1112 to
1292F).
EAS0097
AIR CUT-OFF VALVE
The air...

7-33
AIR INDUCTION SYSTEMFI
A To cylinder #1 and #2
B To cylinder #3 and #41 Air cut-off valve
2 Reed valve
3 To air filter case
EAS00509
AIR INDUCTION SYSTEM DIAGRAMS 

7-34
AIR INDUCTION SYSTEMFI
EAS00510
CHECKING THE AIR INDUCTION SYSTEM
1. Check:

hoses
Loose connection 
 Connect properly.
Cracks / damage 
 Replace.

pipes
Cracks / damage 
 Replace.
2. Check:

 reed valve 
1

 reed valve stopper

reed valve seat
Cracks / damage 
 Replace the reed valve.
3. Measure:

 reed valve bending limit 
a
Out of specification 
 Replace the reed
valve.
Reed valve bending limit
0.4 mm (0.016 in)
1Surface plate
4. Check:

air cut-off valve
Cracks / damage 
 Replace. 

7-35
AIR INDUCTION SYSTEMFI
5. Check

AI system solenoid
a. Remove the AI system solenoid coupler from
the wire harness.
b. Connect the pocket tester (Ω  1) to the AI
system solenoid terminal as shown.
Tester positive probe 
 brown / red 
1
Tester negative probe 
 red / white 2
c. Measure the AI system solenoid resistance.
AI system solenoid resistance
18 
 22 Ω at 20C (68F)
d. Out of specification 
 Replace. 

8-1
8
ELECTRICAL COMPONENTSELEC
9Oil level switch
10Radiator fan motor
11Horn
12Ignition coil
1Main switch
2Front brake light switch
3Starter relay
4Battery
5Fuse box
6Rear brake light switch
7Neutral switch
8Sidestand switch
EAS00729
ELECTRICAL SYSTEM
ELECTRICAL COMPONENTS 

8-2
9Radiator fan motor relay
10Turn signal relay
11Rectifier / regulator
12Throttle position sensor
1Coolant temperature sensor
2Intake air temperature sensor
3Intake air pressure sensor
4Fuel pump
5ECU
6Lean angle cut-off switch
7Starting circuit cut-off relay
8Dimmer relay
ELECTRICAL COMPONENTSELEC