Yamaha Fz1n Service Manual

							
THERMOSTAT
6-9
Below the specified pressure → Replace 
the radiator cap.
Refer to CHECKING THE RADIATOR on 
page 6-3. 
						

							
WATER PUMP
6-10
EAS26500
WAT E R  P U M P
Removing the impeller shaft
Order Job/Parts to remove Q’ty RemarksOil/water pump assembly Refer to OIL PUMP on page 5-58.
Oil pump roter Refer to OIL PUMP on page 5-58.
1 Water pump cover 1
2O-ring 1
3Pin 2
4 Impeller shaft (along with the impeller) 1
5 Water pump seal 1
6 Oil seal 1
7 Bearing 1
8O-ring 1 For installation, reverse the removal 
procedure. 
						

							
WATER PUMP
6-11
EAS26520
DISASSEMBLING THE WATER PUMP
1. Remove: Water pump seal “1”
 Water pump housing “2”
NOTE:
Tap out the water pump seal from the inside of 
the water pump housing.
2. Remove: Oil seal “1”
 Bearing “2”
 Water pump housing “3”
NOTE:
Tap out the bearing and oil seal from the out-
side of the water pump housing.
3. Remove:
 Rubber damper holder “1”
 Rubber damper “2”(from the impeller, with a thin, flat-head 
screwdriver)
NOTE:
Do not scratch the impeller shaft.
EAS26540
CHECKING THE WATER PUMP
1. Check: Water pump housing cover “1”
 Water pump housing “2”
 Impeller “3”
 Rubber damper “4”
 Rubber damper holder “5”
 Water pump seals
Oil seal
Cracks/damage/wear  → Replace.
2. Check:  Bearing
Rough movement  → Replace.
3. Check:  Water pump outlet pipe
Cracks/damage/wear  → Replace.
EAS26560
ASSEMBLING THE WATER PUMP
1. Install:
Oil seal “1”  (into the water pump housing “2”)
NOTE:
 Before installing the oil seal, apply tap water or coolant onto its out surface.
 Install the oil seal with a socket that matches 
its outside diameter. 
						

							
WATER PUMP
6-12
2. Install: Water pump seal “1”  
CAUTION:
ECA14080
Never lubricate the water pump seal sur-
face with oil or grease.
NOTE:
 Install the water pump  seal with the special 
tools.
 Before installing the water pump seal, apply  Yamaha bond No.1215 (Three Bond 
No.1215® ) “2” to the water pump housing 
“3”.
3. Install:  Rubber damper holder “1” 
 Rubber damper “2” 
NOTE:
Before installing the rubber damper, apply tap 
water or coolant onto its outer surface.
4. Measure: Impeller shaft tiltOut of specification  → Repeat steps (3) 
and (4).
CAUTION:
ECA14090
Make sure the rubber damper and rubber 
damper holder are flush with the impeller.
Mechanical seal installer “4” 90890-04078
Water pump seal installer YM-33221-A
Middle driven shaft bearing 
driver “5” 90890-04058
Bearing driver 40 mm YM-04058
Yamaha bond No. 1215 (Three 
Bond No.1215®)
90890-85505
A. Push down.
Impeller shaft tilt limit0.15 mm (0.006 in)
1. Straightedge
2. Impeller 
						

							
WATER PUMP
6-13 
						

							
7
FUEL SYSTEM
FUEL TANK.................................................................................................. 7-1
REMOVING THE FUEL TANK ................................................................ 7-2
REMOVING THE FUEL PUMP............................................................... 7-2
CHECKING THE FUEL PUMP BODY .................................................... 7-2
CHECKING THE FUEL PUMP OPERATION ......................................... 7-2
INSTALLING THE FUEL PUMP ............................................................. 7-2
INSTALLING THE FUEL TANK ............................................................... 7-3
THROTTLE BODIES ..................................................................................... 7-4
CHECKING THE INJECTORS ............................................................... 7-8
CHECKING THE THROTTLE BODIES .................................................. 7-8
CHECKING THE FUEL PR ESSURE............................. ......................... 7-8
ADJUSTING THE THROTTLE POSITION SENSOR ............................. 7-8
ADJUSTING THE SUB-THROTTLE POSITION SENSOR .................... 7-9
CHECKING THE SUB-THROTTLE SERVO MOTOR ........................... 7-10
CHECKING THE THERMO WAX ......................................................... 7-11
ADJUSTING THE THERMO WAX........................................................ 7-11
AIR INDUCTION SYSTEM ......................................................................... 7-13
CHECKING THE AIR INDUCTIO N SYSTEM ....................................... 7-14
INSTALLING THE AIR INDUCT ION SYSTEM ..................................... 7-15 
						

							
FUEL TANK
7-1
EAS26620
FUEL TANK
Removing the fuel tank
Order Job/Parts to remove Q’ty RemarksRider and passenger seat Refer to GENERAL CHASSIS on  page 4-1.
1 Fuel hose 1 Disconnect.
2 Fuel sender coupler 1 Disconnect.
3 Fuel pump coupler 1 Disconnect.
4 Fuel tank drain hose 1 Disconnect.
5 Fuel tank breather hose 1 Disconnect.
6 Fuel tank 1
7 Fuel tank cover 1
8 Fuel pump 1 For installation, reverse the removal 
procedure. 
						

							
FUEL TANK
7-2
EAS26630
REMOVING THE FUEL TANK
1. Extract the fuel in the fuel tank through the fuel tank cap with a pump.
2. Remove:  Fuel hose connector cover
 Fuel hose
 Fuel sender coupler
 Fuel pump coupler
 Fuel tank breather hose
 Fuel tank drain hose
CAUTION:
EC2D1009
 Be sure to disconnect the fuel hose by hand. Do not forcefully disconnect the 
hose with tools.
 Although the fuel has been removed from  the fuel tank be careful when removing 
the fuel hoses, since there may be fuel 
remaining in it.
NOTE:
 To remove the fuel hose from the fuel injec-tion pipe, slide the cover “a” on the end of the 
hose in the direction of the arrow shown and 
then remove the hose.
 Before removing the hoses, place a few rags 
in the area under where it will be removed.
3. Remove: Fuel tank
NOTE:
Do not set the fuel tank down so that the instal-
lation surface of the fuel pump is directly under 
the tank. Be sure to lean the fuel tank in an 
upright position.
EAS26640
REMOVING THE FUEL PUMP
1. Remove: Fuel pump
CAUTION:
ECA14720
 Do not drop the fuel pump or give it a 
strong shock.
 Do not touch the base section of the fuel 
sender.
EAS26670
CHECKING THE FUEL PUMP BODY
1. Check:
 Fuel pump bodyObstruction  → Clean.
Cracks/damage  → Replace fuel pump 
assembly.
2. Check:  Diaphragms and gaskets
Turn/fatigue/cracks  → Replace fuel pump 
assembly.
3. Check:
ValvesCracks/damage  → Replace fuel pump 
assembly.
EAS26690
CHECKING THE FUEL PUMP OPERATION
1. Check:  Fuel pump operation
Refer to CHECKING THE FUEL PRES-
SURE on page 7-8.
EAS26710
INSTALLING THE FUEL PUMP
1. Install: Fuel pump
NOTE:
 Do not damage the installation surface of the fuel tank when installing the fuel pump.
 Always use a new fuel pump gasket.
 Install the fuel pump as shown in the illustra- tion.
 Align the projection “a” on the fuel pump with  the slot in the fuel pump bracket.
 Tighten the fuel pump bolts in stages in a  crisscross pattern and to the specified 
torque.
Fuel pump bolt4 Nm (0.4 m·kg, 2.9 ft·lb) 
						

							
FUEL TANK
7-3
ET2D1023
INSTALLING THE FUEL TANK
1. Install: Fuel hose
 Fuel hose connector cover
CAUTION:
ECA14740
When installing the fuel hose, make sure 
that it is securely connected, and that the 
fuel hose holders are in the correct posi-
tion, otherwise the fuel hose will not be 
properly installed.
NOTE:
Install the fuel hose connector securely onto 
the fuel tank until a distinct “click” is heard, and 
then make sure that it does not come loose.
To install the fuel hose from the fuel injection 
hose, slide the cover “a” on the end of the hose 
in the direction of arrow shown.
2. Install:
 Fuel sender coupler
 Fuel pump coupler
 Fuel tank breather hose
 Fuel tank drain hose
NOTE:
There is white paint mark on the fuel tank 
breather hose.
Refer to CABLE ROUTING on page 2-39. 
						

							
THROTTLE BODIES
7-4
EAS26970
THROTTLE BODIES
Removing the throttle bodies
Order Job/Parts to remove Q’ty RemarksRider and passenger seat Refer to GENERAL CHASSIS on  page 4-1.
Fuel tank Refer to FUEL TANK on page 7-1.
Air filter case Refer to GENERAL CHASSIS on  page 4-1.
1 Sub-wire harness coupler 2 Disconnect.
2 Coolant temperature sensor coupler 1 Disconnect.
3 Thermo wax inret hose 1 Disconnect.
4 Thermo wax outlet hose 1 Disconnect.
5 Idle adjust screw wire 1
6 Throttle body joint clamp 4 Loosen.
7 Throttle bodies 1
8 Throttle cables 2 Disconnect.
9 Throttle body joint 4
10 Fuel hose 1 Disconnect.