Yamaha Fz6 N Service Manual

							
FEATURES
1-2
EAS20170
FEATURES
EAS4S81003
OUTLINE OF FI SYSTEM
The main function of a fuel supply system is to provide fuel to the combustion chamber at the opti-
mum air-fuel ratio in accordance with the engine  operating conditions and the atmospheric tempera-
ture.
In the conventional carburetor system, the air-fuel ratio of the mixture that is supplied to the combus-
tion chamber is created by the volume of the intake air and the fuel that is metered by the jet used in 
the respective carburetor.
Despite the same volume of intake air, the fuel volume requirement varies by the engine operating 
conditions, such as acceleration, deceleration, or operating under a heavy load. Carburetors that 
meter the fuel through the use of jets have been  provided with various auxiliary devices, so that an 
optimum air-fuel ratio can be achieved to accomm odate the constant changes in the operating con-
ditions of the engine.
As the requirements for the engine to deliver  more performance and cleaner exhaust gases 
increase, it becomes necessary to control the air-fuel ratio in a more precise and finely tuned man-
ner. To accommodate this need, this model has adop ted an electronically controlled fuel injection 
(FI) system, in place of the conventional carburetor system. This system can achieve an optimum 
air-fuel ratio required by the engine at all times by  using a microprocessor that regulates the fuel 
injection volume according to the engine oper ating conditions detected by various sensors.
The adoption of the FI system has resulted in  a highly precise fuel supply, improved engine 
response, better fuel economy, and reduced exhaust  emissions. Furthermore, the air induction sys-
tem (AI system) has been placed under computer control together with the FI system in order to 
realize cleaner exhaust gases.
1. Ignition coil
2. Air filter case
3. Intake air temperature sensor
4. Fuel delivery hose
5. Fuel tank
6. Fuel pump
7. Intake air pressure sensor
8. Throttle position sensor
9. Fuel injector
10.Catalytic converter
11.Crankshaft position sensor 12.Coolant temperature sensor
13.Spark plug
14.Pressure regulator
15.Battery
16.ECU
17.Fuel injection system relay
18.Engine trouble warning light
19.Lean angle sensor
20.O
2 sensor 
						

							
FEATURES
1-3
EAS4S81004
FI SYSTEM
The fuel pump delivers fuel to the injector via the fuel filter. The pressure regulator maintains the fuel 
pressure that is applied to the injector at only 250 kPa (2.5 kg/cm
2). Accordingly, when the energiz-
ing signal from the ECU energizes the injector, th e fuel passage opens, causing the fuel to be 
injected into the intake manifold only during the time the passage remains open. Therefore, the 
longer the length of time the injector is energized (injection duration), the greater the volume of fuel 
that is supplied. Conversely, the shorter the length of time the injector is energized (injection dura-
tion), the lesser the volume of fuel that is supplied.
The injection duration and the injection timing are co ntrolled by the ECU. Signals that are input from 
the throttle position sensor, cranksh aft position sensor, intake air pressure sensor, intake tempera-
ture sensor, coolant temperature sensor and O
2 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 accor-
dance with the driving conditions.
1. Fuel pump
2. Pressure regulator
3. Fuel injector
4. Throttle body
5. Intake air temperature sensor
6. Throttle position sensor
7. Intake air pressure sensor
8. ECU
9. Coolant temperature sensor
10.Crankshaft position sensor
11.O
2 sensor
A. Fuel system
B. Control system 
						

							
FEATURES
1-4
EAS4S81005
INSTRUMENT FUNCTIONS
Multi-function meter unit
WARNING
EWA4S81002
Be sure to stop the vehicle before making 
any setting changes to the multi-function 
meter unit.
The multi-function meter unit is equipped with 
the following:
 a speedometer (which shows the riding speed)  a tachometer (which shows engine speed)
 an odometer (which shows the total distance 
traveled)
 two tripmeters (which show the distance trav- eled since they were last set to zero)
 a fuel reserve tripmeter (which shows the  distance traveled since the left segment of 
the fuel meter started flashing)
a clock
 a fuel meter
 a coolant temperature display
 an air intake temperature display
 a self-diagnosis device
 an LCD and tachometer brightness control  mode
NOTE:
 Be sure to turn the key to “ON” before using the “SELECT” and “RESET” buttons.
 For the U.K. only: To switch the speedometer 
and odometer/tripmeter displays between 
kilometers and miles, press the “SELECT” 
button for at least two second. (FZ6-N/FZ6-
NA/FZ6-S/FZ6-SA)
 For the U.K. only: To switch the speedometer  and odometer/tripmeter displays between 
kilometers and miles, press the “SELECT” 
button for at least one second. (FZ6-
NHG(W)/FZ6-NAHG/FZ6-SHG(W)/FZ6-
SAHG)
Tachometer
A. FZ6-N/FZ6-NA/FZ6-S/FZ6-SA
1. Tachometer
2. Speedometer
3. Fuel meter
4. Coolant temperature display
5. “SELECT” button
6. “RESET” button
7. Clock/air intake temperature/CO adjusting 
mode tachometer display
8. Odometer/tripmeter/fuel reserve tripmeter/ tachometer
B. FZ6-NHG(W)/FZ6-NAHG/FZ6-SHG(W)/ FZ6-SAHG
1. Coolant temperature display/air intake tem- perature display
2. Speedometer
3. Tachometer
4. Odometer/tripmeter/fuel reserve tripmeter
5. “SELECT” button
6. “RESET” button
7. Clock
8. Fuel meter
A. FZ6-N/FZ6-NA/FZ6-S/FZ6-SA 
						

							
FEATURES
1-5
The electric tachometer allows the rider to 
monitor the engine speed and keep it within 
the ideal power range.
When the key is turned to “ON”, the tachome-
ter needle will sweep once across the r/min 
range and then return to zero r/min in order to 
test the electrical circuit.
CAUTION:
ECA4S81004
Do not operate the engine in the tachome-
ter red zone.
Red zone: 14000 r/min and above
Clock mode
The clock is displayed when the key is turned 
to “ON”. In addition, the clock can be displayed 
for 10 seconds by pushing the “SELECT” but-
ton when the main switch is in the “OFF” or 
“LOCK” position.
To set the clock
1 Turn the key to “ON”.
2 Push the “SELECT” button and “RESET” but-ton together for at least two seconds. 3 When the hour digits start flashing, push the 
“RESET” button to set the hours.
4 Push the “SELECT” button, and the minute  digits will start flashing.
5 Push the “RESET” button to set the minutes.
6 Push the “SELECT” button and then release 
it to start the clock.
Odometer and tripmeter modes (FZ6-N/FZ6-NA/
FZ6-S/FZ6-SA)
Push the “SELECT” button to switch the dis-
play between the odometer mode “ODO” and 
the tripmeter modes “TRIP A” and “TRIP B” in 
the following order:
“ODO”  → “TRIP 1”  → “TRIP 2”  → “TRIP F”  → 
“E”  → “ODO”
When the fuel amount in the fuel tank 
decreases to 3.6 L (0.90 US gal) (0.79 
Imp.gal), the bottom segment of the fuel meter 
will start flashing, and the odometer display will 
automatically change to the fuel reserve trip-
meter mode “TRIP F” and start counting the 
distance traveled from that point. In that case, 
push the “SELECT” button to switch the dis-
play between the various tripmeter and odom-
eter modes in the following order:
“TRIP F”  → “E”  → “ODO”  → “TRIP 1”  → “TRIP 
2”  → “TRIP F”
To reset a tripmeter, select it by pushing the 
“SELECT” button, and then push the “RESET” 
button for at least one second. If you do not 
reset the fuel reserve tripmeter manually, it will 
reset itself automatically and the display will 
return to the prior mode after refueling and 
traveling 5 km (3 mi).
B. FZ6-NHG(W)/FZ6-NAHG/FZ6-SHG(W)/ FZ6-SAHG
1. Tachometer
2. Tachometer red zone.
A. FZ6-N/FZ6-NA/FZ6-S/FZ6-SA
B. FZ6-NHG(W)/FZ6-NAHG/FZ6-SHG(W)/ FZ6-SAHG
1. Clock
2. Speedometer
1. Odometer/tripmeter/fuel reserve tripmeter/ tachometer 
						

							
FEATURES
1-6
Odometer and tripmeter modes (FZ6-NHG(W)/
FZ6-NAHG/FZ6-SHG(W)/FZ6-SAHG)
Push the “SELECT” button to switch the dis-
play between the odometer mode “ODO” and 
the tripmeter modes “TRIP A” and “TRIP B” in 
the following order:
“TRIP A” → “TRIP B”  → “ODO”  → “TRIP A”
When the fuel amount in the fuel tank 
decreases to 3.4 L (0.90 US gal) (0.75 
Imp.gal), the left segment of the fuel meter will 
start flashing, and the odometer display will 
automatically change to the fuel reserve trip-
meter mode “F TRIP” and start counting the 
distance traveled from that point. In that case, 
push the “SELECT” button to switch the dis-
play between the various tripmeter and odom-
eter modes in the following order:
“F-TRIP”  → “TRIP A”  → “TRIP B”  → “ODO”  → 
“F-TRIP”
To reset a tripmeter, select it by pushing the 
“SELECT” button, and then push the “RESET” 
button for at least one second. If you do not 
reset the fuel reserve tripmeter manually, it will 
reset itself automatically and the display will 
return to the prior mode after refueling and 
traveling 5 km (3 mi).
Fuel meter
The fuel meter indicates the amount of fuel in 
the fuel tank. The display segments of the fuel 
meter disappear towards “E” (Empty) as the 
fuel level decreases. When only one segment 
is left near “E”, refuel as soon as possible.
NOTE:
This fuel meter is equipped with a self-diagno-
sis system. If the electrical circuit is defective, 
the following cycle will be repeated until the 
malfunction is corrected:  “E” (Empty), “F” (Full) 
and symbol “ ” will flash eight times, then go 
off for approximately 3 seconds. If this occurs, 
have a Yamaha dealer check the electrical cir-
cuit.
1. Odometer/tripmeter/fuel reserve tripmeter
A. FZ6-N/FZ6-NA/FZ6-S/FZ6-SA
B. FZ6-NHG(W)/FZ6-NAHG/FZ6-SHG(W)/ FZ6-SAHG
1. Fuel meter 
						

							
FEATURES
1-7
Coolant temperature mode (FZ6-NHG(W)/FZ6-
NAHG/FZ6-SHG(W)/FZ6-SAHG)
The coolant temperature display indicates the 
temperature of the coolant.
Push the “RESET” button to switch the coolant 
temperature display to the air intake tempera-
ture display.
NOTE:
When the coolant temperature display is 
selected, “C” is displayed for one second, and 
then the coolant temperature is displayed.
CAUTION:
ECA4S81009
Do not operate the engine if it is over-
heated.
Air intake temperature mode
The air intake temperature display indicates 
the temperature of the air drawn into the air fil-
ter case. Push the “RESET” button to switch 
the coolant temperature display to the air 
intake temperature display.
NOTE:
 Even if the air intake temperature is set to be displayed, the coolant temperature warning 
light comes on when the engine overheats.
 When the key is turned to “ON”, the coolant 
temperature is automatically displayed, even 
if the air intake temperature was displayed 
prior to turning the key to “OFF”.
 When the air intake temperature display is  selected, “A” is displayed for one second, 
and then the air intake temperature is dis-
played. (FZ6-NHG(W)/FZ6-NAHG/FZ6-
SHG(W)/FZ6-SAHG)
Self-diagnosis device
This model is equipped with a self-diagnosis 
device for various electrical circuits.
If any of those circuits are defective, the engine 
trouble warning light will come on, and then the 
display will indicate a  two-digit error code (e.g., 
11, 12, 13).
This model is also equipped with a self-diagno-
sis device for the immobilizer system.
1. Coolant temperature display
A. FZ6-N/FZ6-NA/FZ6-S/FZ6-SA
B. FZ6-NHG(W)/FZ6-NAHG/FZ6-SHG(W)/ FZ6-SAHG
1. Air intake temperature display
A. FZ6-N/FZ6-NA/FZ6-S/FZ6-SA
B. FZ6-NHG(W)/FZ6-NAHG/FZ6-SHG(W)/ FZ6-SAHG
1. Error code display 
						

							
FEATURES
1-8
If any of the immobilizer system circuits are 
defective, the immobilizer system indicator 
light will flash, and then the display will indicate 
a two-digit error code (e.g., 51, 52, 53).
NOTE:
If the display indicates error code 52, this could 
be caused by transponder interference. If this 
error code appears, try the following.
1 Use the code re-registering key to start the 
engine.
NOTE:
Make sure there are no other immobilizer keys 
close to the main switch, and do not keep more 
than one immobilizer key on the same key ring! 
Immobilizer system keys may cause signal 
interference, which may prevent the engine 
from starting
2 If the engine starts, turn it off and try starting the engine with the standard keys.
3 If one or both of the standard keys do not  start the engine, take the vehicle, the code 
re-registering key and both standard keys to 
a Yamaha dealer and have the standard keys 
re-registered. 
If the display indicates any error codes, note 
the code number, and then have a Yamaha 
dealer check the vehicle.
CAUTION:
ECA4S81010
If the display indicates an error code, the 
vehicle should be checked as soon as pos-
sible in order to avoid engine damage.
LCD and tachometer brightness control mode
(FZ6-NHG(W)/FZ6-NAHG/FZ6-SHG(W)/FZ6-
SAHG)
This function allows you to adjust the bright-
ness of the LCD and the tachometer panel and 
needle to suit the outside lighting conditions.
To set the brightness
1 Turn the key to “OFF”.
2 Push and hold the “SELECT” button.
3 Turn the key to “ON”, and then release the  “SELECT” button after five seconds.
4 Push the “RESET” button to select the  desired brightness level.
5 Push the “SELECT” button to confirm the 
selected brightness level. The display will 
return to the odometer or tripmeter mode.
1. Tachometer panel
2. Tachometer needle
3. LCD
4. Brightness level 
						

							
FEATURES
1-9
EAS4S81007
OUTLINE OF THE ABS
1 The Yamaha ABS (anti-lock brake system) features a dual electronic control system, which acts on 
the front and rear brakes independently.
2 The ABS features a compact and lightweight design  to help maintain the basic maneuverability of 
the vehicle.
3 The hydraulic unit, which is the main component of  the ABS, is centrally located on the vehicle to 
increase mass centralization.
ABS layout
ABS
The operation of the Yamaha ABS brakes is the same  as conventional brakes on other vehicles, with 
a brake lever for operating the front brake and a brake pedal for operating the rear brake.
When wheel lock is detected during emergency brak ing, hydraulic control is performed by the 
hydraulic system on the front and rear brakes independently.
Useful terms
 Wheel speed: The rotation speed of the front and rear wheels.
 Chassis speed:
The speed of the chassis.
When the brakes are applied, wheel speed and chassis speed are reduced. However, the chassis 
travels forward by its inertia even though the wheel speed is reduced.
1. ABS warning light
2. ABS ECU (electronic control unit)
3. ABS motor relay
4. Hydraulic unit (HU)
5. Rear brake caliper 6. Rear wheel sensor
7. Rear wheel sensor rotor
8. Front brake caliper
9. Front wheel sensor
10.Front wheel sensor rotor 
						

							
FEATURES
1-10
Brake force:The force applied by braking to reduce the wheel speed.
 Wheel lock: A condition that occurs when the rotation of one or both of the wheels has stopped, but the vehicle 
continues to travel.
 Side force: The force on the tires which supports the vehicle when cornering.
 Slip ratio:
When the brakes are applied, slipping occurs betw een the tires and the road surface. This causes 
a difference between the wheel speed and the chassis  speed. Slip ratio is the value that shows the 
rate of wheel slippage and is defined by the following formula.
0%: There is no slipping between the wheel and the road surface. The chassis speed is equal to 
the wheel speed.
100%: The wheel speed is “0”, but the chassis is moving (i.e., wheel lock).
Brake force and vehicle stability
When the brake pressure is increased, wheel speed  is reduced. Slipping occurs between the tire 
and the road surface and brake force is generated. The  limit of this brake force is determined by the 
friction force between the tire and the road surface and is closely related to wheel slippage. Wheel 
slippage is represented by the slip ratio.
Side force is also closely related to wheel slippage . See figure “A”. If the brakes are applied while 
keeping the proper slip ratio, it  is possible to obtain the maximum brake force without losing much 
side force. ABS allows full use of the tires’ capabili ties even on slippery road surfaces or less slip-
pery road surfaces. See figure “B”. Slip ratio =
Chassis speed 
– Wheel speed
× 100 (%)
Chassis speed
a. Friction force between the tire and road  surface
b. Brake force c. Side force
d. Slip ratio (%)
e. Less slippery road surface 
						

							
FEATURES
1-11
Wheel slip and hydraulic control
The ABS ECU calculates the wheel speed of each wheel according to the rotation signal received 
from the front and rear wheel sensors. In addi tion, the ABS ECU calculates the vehicle chassis 
speed and the rate of speed reduction based on the wheel speed values.
The difference between the chassis speed and the wheel  speed calculated in the slip ratio formula is 
equal to the wheel slip. When the wheel speed is  suddenly reduced, the wheel has a tendency to 
lock. When the wheel slip and the wheel speed redu ction rate exceed the preset values, the ABS 
ECU determines that the wheel has a tendency to lock.
If the slip is large and the whee l has a tendency to lock (point A  in the following figure), the ABS 
ECU reduces the brake fluid pressure in the brak e caliper. The ABS ECU increases the pressure of 
the brake fluid in the brake caliper when the tendenc y to lock has diminished (point B in the following 
figure).
ABS operation and vehicle control
If the ABS starts operating, there is a tendency of  the wheel to lock, and the vehicle is approaching 
the limit of control. To make the rider aware of this condition, the ABS has been designed to gener-
ate a reaction-force pulsating action in t he brake lever and brake pedal independently.
NOTE:
When the ABS is activated, a pulsating action may be  felt at the brake lever or brake pedal, but this 
does not indicate a malfunction.
The higher the side force on a tire, the less traction there is available for braking. This is true 
whether the vehicle is equ ipped with ABS or not. Therefore, s udden braking while cornering is not 
recommended. Excessive side force,  which ABS cannot prevent, could cause the tire to slip side-
ways.
f. Controlling zone
g. Slippery road surface
a. Vehicle speed
b. Wheel speed
c. Pressurized d. Depressurized
e. Brake force