Yamaha Fz6 N Service Manual

THROTTLE BODIES
7-4
EAS26970
THROTTLE BODIES
Removing the throttle bodies
Order Job/Parts to remove Q’ty RemarksSeat Refer to GENERAL CHASSIS on page 4-1.
Left front cowling inner panel (with cowling) Refer to GENERAL CHASSIS on page 4-1.
Right front cowling inner panel (with cowlin g) Refer to GENERAL CHASSIS on page 4-1.
Fuel tank Refer to FUEL TANK on page 7-1.
Battery Refer to GENERAL CHASSIS on page 4-1.
Air filter case Refer to GENERAL CHASSIS on page 4-1.
Battery box and battery box bracket Refer...

THROTTLE BODIES
7-5
Removing the injectors
Order Job/Parts to remove Q’ty Remarks1 Throttle position sensor coupler 1 Disconnect.
2 Intake air pressure sensor coupler 1 Disconnect.
3 Cylinder #1 injector coupler 1 Disconnect.
4 Cylinder #2 injector coupler 1 Disconnect.
5 Cylinder #3 injector coupler 1 Disconnect.
6 Cylinder #4 injector coupler 1 Disconnect.
7 Sub-wire harness 1
8 Negative pressure hose 1
9 Intake air pressure sensor 1
10 Fuel distributor 1
11 Injector 4
12 Throttle position sensor 1
13...

THROTTLE BODIES
7-6
EAS26980
CHECKING THE INJECTORS
1. Check: Injectors
Damage  → Replace.
EAS26990
CHECKING THE THROTTLE BODIES
1. Check:
 Throttle bodies Cracks/damage  → Replace the throttle 
bodies as a set.
2. Check:  Fuel passages Obstructions  → Clean.
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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.
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3. Check:...

THROTTLE BODIES
7-7
c. Measure the throttle position sensor volt-age.
d. Adjust the throttle position sensor angle so  that the voltage is within the specified 
range.
e. After adjusting the th rottle position sensor 
angle, tighten the throttle position sensor 
screws.
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 Positive tester probe Ye l l o w  “ 1 ”
 Negative tester probe
Black/Blue “2”
Digital circuit tester 90890-03174
Model 88 Multimeter with 
tachometer
YU-A1927
Output voltage (at idle)Adjusted by tachometer 

THROTTLE BODIES
7-8 

AIR INDUCTION SYSTEM
7-9
EAS27040
AIR INDUCTION SYSTEM 

AIR INDUCTION SYSTEM
7-10
1. Air cut-off valve
2. Reed valve
3. To air filter case
A. To cylinder #1 and #2
B. To cylinder #3 and #4 

AIR INDUCTION SYSTEM
7-11
Removing the air cut-off valve assembly and hoses
Order Job/Parts to remove Q’ty RemarksSeat Refer to GENERAL CHASSIS on page 4-1.
Left front cowling inner panel (with cowling) Refer to GENERAL CHASSIS on page 4-1.
Right front cowling inner panel (with cowlin g) Refer to GENERAL CHASSIS on page 4-1.
Fuel tank Refer to FUEL TANK on page 7-1.
Battery Refer to GENERAL CHASSIS on page 4-1.
Air filter case Refer to GENERAL CHASSIS on page 4-1.
Battery box and battery box bracket...

AIR INDUCTION SYSTEM
7-12
EAS27060
CHECKING THE AIR INDUCTION SYSTEM
Air injection
The air induction system burns unburned 
exhaust gases by injecting fresh air (second-
ary air) into the exhaust port, reducing the 
emission of hydrocarbons. When there is neg-
ative 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 700°C.
Air cut-off valve
The air cut-off...

AIR INDUCTION SYSTEM
7-13
2. Install: Reed valve cover