fuel filter YAMAHA YZ450F 2013 User Guide

3-25
ELECTRICAL
TROUBLESHOOTING
The following guide for troubleshooting does not cover all the possible causes of problems. If the following problems occur,
perform the specified checks or maintenance jobs. If a problem occurs that is not listed in this manual or if the problem
cannot be corrected by the procedures provided in this manual, contact your Yamaha dealer.
Engine starting problems, engine idling speed problems, and medium and high-speed performance problems
• Engine does not start even though the kickstarter is pushed.
• Engine starts, but soon stops.
Engine idling speed problems
• Engine idling speed fluctuates.
• Engine idling speed is high.
• Engine idling speed is low.
Medium and high-speed performance problems
• Engine speed does not increase.
• Engine knocks.
• Engine speed increases suddenly.
• Loss of engine power.
INSPECTION STEPS
If the aforementioned problems have occurred, perform the following inspection steps in the order given.
Check that the fuel tank is filled with fresh gaso-
line.No good→
Fill the fuel tank.
OK↓
Check that the fuel tank breather hose is not
clogged. (Refer to "INCLUDED PARTS" section
in the CHAPTER 1.)No good→
Repair or replace.
OK↓
Adjusting the engine idling speed(Refer to "AD-
JUSTING THE ENGINE IDLLING SPEED" sec-
tion in the CHAPTER 3.)No good→
Adjust.
OK↓
Check that the fuel hose is connected properly
and is not kinked or pinched.No good→
Repair.
OK↓
Check the spark plug for dirt, the spark plug gap,
and the spark plug cap. (Refer to "CHECKING
THE SPARK PLUG" section in the CHAPTER 3.)No good→
Clean or adjust.
OK↓
Check that the air filter element is installed cor-
rectly and is not clogged. (Refer to "CLEANING
THE AIR FILTER" section in the CHAPTER 3.)No good→
Clean or repair.
OK↓
Checking the sensors, injector and ignition coil
connection.No good→
Repair or replace.
OK↓
Installed condition of ECU (Refer to "CHECKING
THE ECU" section in the CHAPTER 7.)No good→
Repair.
OK↓
Check the assembled condition of the throttle
body, and check the throttle valve and its sur-
rounding parts for dirt.No good→
Repair or clean.
OK↓
Consult a Yamaha dealer.

4-5
RADIATOR
RADIATOR
REMOVING THE RADIATOR
Order Part name Q'ty Remarks
Drain the coolant.Refer to "CHANGING THE COOLANT" sec-
tion in the CHAPTER 3.
SeatRefer to "SEAT AND SIDE COVERS" sec-
tion.
Fuel tank Refer to "FUEL TANK" section in the CHAP-
TER 6.
Air filter caseRefer to "THROTTLE BODY" section in the
CHAPTER 6.
1 Radiator guard 2
2 Radiator hose clamp 8 Only loosening.
3 Right radiator 1
4 Radiator hose 2 1
5 Radiator hose 4 1
6 Radiator hose 3 1
7 Pipe 2/O-ring 1/1
8 Radiator breather hose 1
9 Left radiator 1
10 Radiator hose 1 1

4-45
ENGINE REMOVAL
ENGINE REMOVAL
REMOVING THE ELECTRONIC PARTS
Order Part name Q'ty Remarks
Hold the machine by placing the suitable stand
under the frame.Refer to "HANDLING NOTE".
SeatRefer to "SEAT AND SIDE COVERS" sec-
tion.
Fuel tankRefer to "FUEL TANK" section in the CHAP-
TER 6.
Air filter caseRefer to "THROTTLE BODY" section in the
CHAPTER 6.
Radiator Refer to "RADIATOR" section.
1 Rectifier/regulator 1
2 Ignition coil bracket 1
3 Ignition coil 1
4 Atmospheric pressure sensor 1
5 Condenser 1
6 AC magneto lead 1 Disconnect.
7 Coolant temperature sensor coupler 1 Disconnect.

6-4
THROTTLE BODY
THROTTLE BODY
REMOVING THE THROTTLE BODY
Order Part name Q'ty Remarks
SeatRefer to "SEAT AND SIDE COVERS" section
in the chapter 4.
Air scoop (left/right)Refer to "SEAT AND SIDE COVERS" section
in the chapter 4.
Fuel tank Refer to "FUEL TANK" section.
1 Cover 1
2 Air filter case 1
3 Fuel hose 1
4 Fuel injector coupler 1 Disconnect.
5 Intake air pressure sensor coupler 1 Disconnect. (I.D. MARK "2")
6 Throttle cable cover 1
7 Throttle cable 2
8 Throttle body 1
9 Throttle body joint 1

7-37
ELECTRICAL COMPONENTS
3. Connect the FI diagnostic tool
sub-wire harness to a battery, and
then set the switch on the harness
to "ON".
When checking the atmospheric
pressure sensor, do not start the
engine.
4. Measure the atmospheric pres-
sure sensor output voltage.
Out of specification→Replace.
CHECKING THE RECTIFIER/
REGULATOR
1. Connect:
• Connect the tester to the coupler
for connecting optional part
Tester (+) lead→ Red lead "1"
Tester (-) lead→ Black/White lead
"2"
2. Start the engine.
3. Check:
• Rectifier/regulato output voltage
Out of specification → Replace.
4. Stop the engine.CHECKING THE FUEL INJECTORS
1. Remove:
•Seat
•Fuel tank
• Air filter case
2. Check:
•Injector resistance
3. Connect:
•Tester
Tester (+) lead → Injector termi-
nal "1"
Tester (-) lead → Injector termi-
nal "2"
Out of specification→Replace. Test harness S–pressure
sensor (3P):
YU-03207/90890-03207
Output volt-
ageTester se-
lector posi-
tion
3.4–3.8 V DCV
Output volt-
ageTester se-
lector posi-
tion
14.1–14.9 V DCV
Lg
R
B/W
Injector re-
sistanceTester se-
lector posi-
tion
12.0 Ω
(20°C, 68°F) Ω×10