Yamaha Fz1n Service Manual

							
ENGINE
3-6
If the valve pad is marked “158”, the pad 
thickness is 1.58 mm (0.062in)
d. Calculate the sum of the values obtained in  steps (b) and (c) to determine the required 
valve pad thickness and the valve pad 
number.
Example:
1.58 mm (0.062 in) + 0.05 mm (0.002 in) = 
1.63 mm (0.064 in)
The valve pad number is 163.
e. Round off the valve pad number according  to the following table, and then select the 
suitable valve pad.
NOTE:
Refer to the following table for the available 
valve pads.
Example:
Valve pad number = 163
Rounded value = 165
New valve pad number = 165
f. Install the new valve pad “1” and the valve  lifter “2”.
NOTE:
 Lubricate the valve lifter with engine oil.
 Install the valve lifter and the valve pad in the correct place.
 The valve lifter must turn smoothly when 
rotated by hand. g. Install the exhaust and intake camshafts, 
timing chain and camshaft caps.
NOTE:
 Refer to CAMSHAFTS on page 5-10.
 Lubricate the camshaft bearings, camshaft lobes and camshaft journals.
 First, install the exhaust camshaft.
 Align the camshafts marks with the camshaft 
cap marks.
 Turn the crankshaft clockwise several full 
turns to seat the parts.
h. Measure the valve clearance again.
i. If the valve clearance is still out of specifi- cation, repeat all of the valve clearance 
adjustment steps until the specified clear-
ance is obtained.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
7. Install: All removed parts
NOTE:
For installation, reverse the removal proce-
dure.
EAS20570
SYNCHRONIZING THE THROTTLE BODIES
NOTE:
Prior to synchronizing the throttle bodies, the 
valve clearance and the engine idling speed 
should be properly adjusted and the ignition 
timing should be checked.
1. Stand the vehicle on a level surface.
NOTE:
Place the vehicle on a suitable stand.
2. Remove:
 Rider and passenger seat
Last digit Rounded value
0,1,2 0
3,4,5,6 5 7,8,9 10
Valve pad range Nos. 150–240
Valve pad thickness 1.50–2.40 mm
(0.0591–0.0945 in)
Available valve pads 25 thicknesses in
0.05 mm (0.002 in)
increments
Camshaft cap bolt
10 Nm (1.0 m·kg, 7.2 ft·lb) 
						

							
ENGINE
3-7
Refer to GENERAL CHASSIS on page 4-
1.
 Fuel tank Refer to FUEL TANK on page 7-1.
3. Remove:
 Synchronizing hoses “1”
4. Install:  Vacuum gauge “1”(onto the synchronizing hose)
 Digital tachometer
(near the spark plug)
5. Install:  Fuel tankRefer to FUEL TANK on page 7-1.
6. Start the engine and let it warm up for sev- eral minutes.
7. Check:
 Engine idling speedOut of specification  → Adjust.
Refer to ADJUSTING THE ENGINE 
IDLING SPEED on page 3-9.
8. Adjust:  Throttle body synchronization
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. With throttle body #3 as standard, adjust 
throttle bodies #1, #2, and #4 using the air 
screw “1”.
NOTE:
 After each step, rev the engine two or three times, each time for less than a second, and 
check the synchronization again.
 If the air screw is removed, turn the screw 3/
4 turn in and be sure to synchronize the 
throttle body.
CAUTION:
EC2D1080
Do not use the throttle valve adjusting 
screws to adjust the throttle body synchro-
nization.
NOTE:
The difference in vacuum pressure between 
two throttle bodies should not exceed 1.33 kPa 
(10mmHg, 0.39 inHg).
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
9. Measure: Engine idling speed
Out of specification  → Adjust.
Vacuum gauge
90890-03094
Carburetor synchronizer
YU-44456
Engine idling speed1.100–1.300 r/min
Vacuum pressure at engine 
idling speed
30 kPa (225 mmHg, 8.9 inHg) 
						

							
ENGINE
3-8
Make sure that the vacuum pressure is 
within specification.
10. Stop the engine and remove the measuring  equipment.
11. Adjust:
 Throttle cable free playRefer to ADJUSTING THE THROTTLE 
CABLE FREE PLAY on page 3-9.
12. Install:  Synchronizing hoses
Fuel tankRefer to FUEL TANK on page 7-1.
 Rider and passenger seat Refer to GENERAL CHASSIS on page 4-
1.
EAS20600
ADJUSTING THE EXHAUST GAS VOLUME
NOTE:
Be sure to set the CO density level to stan-
dard, and then adjust the exhaust gas volume.
1. Turn the main switch to “OFF” and set the  engine stop switch to “ON”.
2. Simultaneously press and hold the 
“SELECT” and “RESET” buttons, turn the 
main switch to “ON”, and continue to press 
the buttons for 8 seconds or more.
NOTE:
“dI” appears on the clock LCD.
3. Press the “SELECT” button to select the CO adjustment mode “Co” “1” or the diag-
nostic mode “dI”. 4. After selecting “Co”, simultaneously press 
the “SELECT” and “RESET” buttons for 2 
seconds or more to execute the selection.
NOTE:
The selected cylinder number appears on the 
clock LCD.
 To decrease the selected cylinder number, press the “RESET” button.
 To increase the selected cylinder number, 
press the “SELECT” button.
5. After selecting the cylinder, simultaneously  press the “SELECT” and “RESET” buttons 
for 2 seconds or more to execute the selec-
tion.
6. Change the CO adjustment volume by  pressing the “SELECT” and “RESET” but-
tons.
NOTE:
The CO adjustment volume appears on the 
tripmeter LCD.
 To decrease the CO adjustment volume, 
press the “RESET” button.
 To increase the CO adjustment volume, 
press the “SELECT” button.
7. Release the switch to execute the selec- tion.
Throttle cable free play
(at the flange of the throttle 
grip)
3.0–5.0 mm (0.12–0.20 in) 
						

							
ENGINE
3-9
8. Simultaneously press the “SELECT” and “RESET” buttons to return to the cylinder 
selection (step 5).
9. Turn the main switch to “OFF” to cancel the  mode.
EAS20610
ADJUSTING THE ENGINE IDLING SPEED
NOTE:
Prior to adjusting the engine idling speed, the 
throttle bodies’ synchronization should be 
adjusted properly, the air filter element should 
be clean, and the engine should have ade-
quate compression.
1. Start the engine and let it warm up for sev-
eral minutes.
2. Install:
 Digital tachometer(onto the spark plug lead of cylinder #1)
3. Check:
 Engine idling speedOut of specification  → Adjust.
4. Adjust:  Engine idling speed
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Turn the idle adjusting screw “1” in direction  “a” or “b” until the specified engine idling 
speed is obtained.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
5. Adjust: Throttle cable free play
Refer to ADJUSTING THE THROTTLE 
CABLE FREE PLAY on page 3-9.
EAS20630
ADJUSTING THE THROTTLE CABLE FREE 
PLAY
NOTE:
Prior to adjusting the throttle cable free play, 
the engine idling speed should be adjusted 
properly.
1. Check: Throttle cable free play “a”
Out of specification  → Adjust.
2. Adjust:  Throttle cable free play
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
Handlebar side
a. Loosen the locknut “1”.
b. Turn the adjusting nut “2” in direction “a” or  “b” until the specified throttle cable free 
play is obtained.
Engine idling speed1,100–1,300 r/min
Direction “a” Engine idling speed is increased.
Direction “b”
Engine idling speed is decreased.
Throttle cable free play(at the flange of the throttle 
grip)
3.0–5.0 mm (0.12–0.20 in)
Throttle cable free play
(at the flange of the throttle 
grip)3.0–5.0 mm (0.12–0.20 in)
Direction “a” Throttle cable free play is increased.
Direction “b” Throttle cable free play is decreased. 
						

							
ENGINE
3-10
c. Tighten the locknut.
WARNING
EW2D1001
After adjusting the throttle cable free play, 
start the engine and turn the handlebars to 
the right and to the left to ensure that this 
does not cause the engine idling speed to 
change.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS20680
CHECKING THE SPARK PLUGS
The following procedure applies to all of the 
spark plugs.
1. Remove: Radiator upper bolts
 Radiator lower bolt
Refer to RADIATOR on page 6-1.
2. Remove:
 Ignition coils
 Spark plugs
CAUTION:
ECA13320
Before removing the spark plugs, blow 
away any dirt accumulated in the spark 
plug wells with compressed air to prevent it 
from falling into the cylinders.
3. Check: Spark plug typeIncorrect  → Change.
4. Check:  Electrode “1”Damage/wear  → Replace the spark plug.
 Insulator “2” Abnormal color  → Replace the spark plug.
Normal color is medium-to-light tan.
5. Clean:  Spark plug(with a spark plug cleaner or wire brush) 6. Measure:
 Spark plug gap “a”
(with a wire thickness gauge)
Out of specification  → Regap.
7. Install:  Spark plugs
 Ignition coils
NOTE:
Before installing the spark plug, clean the 
spark plug and gasket surface.
8. Install:
 Radiator upper bolts
 Radiator lower boltRefer to RADIATOR on page 6-1.
EAS20710
MEASURING THE COMPRESSION PRES-
SURE
The following procedure applies to all of the 
cylinders.
NOTE:
Insufficient compression pressure will result in 
a loss of performance.
1. Measure:
 Valve clearanceOut of specification  → Adjust.
Refer to ADJUSTING THE VALVE 
CLEARANCE on page 3-4.
2. Start the engine, warm it up for several 
minutes, and then turn it off.
3. Remove:  Ignition coils
 Spark plugs
Spark plug type (manufacturer)
CR9EK (NGK)
Spark plug gap0.6–0.7 mm
(0.0236–0.0276 in)
Spark plug
13 Nm (1.3 m·kg, 9.4 ft·lb) 
						

							
ENGINE
3-11
CAUTION:
ECA13340
Before removing the spark plugs, use com-
pressed air to blow away any dirt accumu-
lated in the spark plug wells to prevent it 
from falling into the cylinders.
4. Install: Compression gauge “1”
 Extension
5. Measure:  Compression pressure
Out of specification  → Refer to steps (c) 
and (d).
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Set the main switch to “ON”.
b. With the throttle wide open, crank the  engine until the reading on the compres-
sion gauge stabilizes.
WARNING
EW2D1002
To prevent sparking, ground all spark plug 
leads before cranking the engine.
NOTE:
The difference in compression pressure 
between cylinders should not exceed 100 kPa 
(1 kg/cm², 1 bar, 14.22 psi).
c. If the compression pressure is above the 
maximum specification, check the cylinder 
head, valve surfaces and piston crown for 
carbon deposits.
Carbon deposits  → Eliminate.
d. If the compression pressure is below the  minimum specification, pour a teaspoonful 
of engine oil into the spark plug bore and 
measure again.
Refer to the following table.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
6. Install:
 Spark plug
7. Install:  Ignition coils
EAS20730
CHECKING THE ENGINE OIL LEVEL
1. Stand the vehicle on a level surface.
NOTE:
 Place the vehicle on a suitable stand.
 Make sure the vehicle is upright.
2. Start the engine, warm it up for several  minutes, and then turn it off.
3. Check:
 Engine oil levelThe engine oil level should be between the 
minimum level mark “a” and maximum level 
mark “b”.
Below the minimum level mark  → Add the 
recommended engine oil to the proper 
level.
Compression gauge
90890-03081
Engine compression tester
YU-33223
Compression pressure (at sea
level) Minimum
1290 kPa (12.90 kg/cm
2,12.90 
bar, 183.5 psi)
Standard
1480 kPa (14.80 kg/cm
2,14.80 
bar, 210.5 psi)
Maximum
1660 kPa (16.60 kg/cm
2, 16.60 
bar, 236.1 psi)
Compression pressure (with oil applied into 
the cylinder)
Reading Diagnosis
Higher than without 
oil Piston ring(s) wear or 
damage 
→ Repair.
Same as without oil Piston, valves, cylin- der head gasket or 
piston possibly defec-
tive → Repair.
Spark plug
13 Nm (1.3 m·kg, 9.4 ft·lb) 
						

							
ENGINE
3-12
CAUTION:
ECA13360
 Engine oil also lubricates the clutch and the wrong oil types or additives could 
cause clutch slippage. Therefore, do not 
add any chemical additives or use engine 
oils with a grade of CD “c” or higher and 
do not use oils labeled “ENERGY CON-
SERVING II” “d” or higher.
 Do not allow foreign materials to enter the 
crankcase.
NOTE:
Before checking the engine oil level, wait a few 
minutes until the oil has settled. 4. Start the engine, warm it up for several 
minutes, and then turn it off.
5. Check the engine oil level again.
NOTE:
Before checking the engine oil level, wait a few 
minutes until the oil has settled.
EAS20790
CHANGING THE ENGINE OIL
1. Start the engine, warm it up for several  minutes, and then turn it off.
2. Place a container under the engine oil drain  bolt.
3. Remove:  Engine oil filler cap “1”
 Engine oil drain bolt “2”(along with the gasket)
4. Drain:  Engine oil(completely from the crankcase)
Recommended oil
Refer to the chart for the 
engine oil grade which is best 
suited for certain atmo-
spheric temperatures.
API standard
SE or higher grade
ACEA standard G4 or G5 
						

							
ENGINE
3-13
5. If the oil filter cartridge is also to be replaced, perform the following procedure.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Remove the oil filter cartridge “1” with an oil filter wrench “2”.
b. Lubricate the O-ring “3” of the new oil filter  cartridge with a thin coat of engine oil.
CAUTION:
ECA13390
Make sure the O-ring “3” is positioned cor-
rectly in the groove of the oil filter car-
tridge.
c. Tighten the new oil filter cartridge to speci-fication with an oil filter wrench.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
6. Replace:
 Engine oil drain bolt gasket 
7. Install:  Engine oil drain bolt(along with the new gasket) 8. Fill:
Crankcase
(with the specified amount of the recom-
mended engine oil)
9. Install:  Engine oil filler cap
10. Start the engine, warm it up for several 
minutes, and then turn it off.
11. Check:  Engine
(for engine oil leaks)
12. Check:  Engine oil level
Refer to CHECKING THE ENGINE OIL 
LEVEL on page 3-11.
EAS20820
MEASURING THE ENGINE OIL PRESSURE
1. Check: Engine oil levelBelow the minimum level mark “a”  → Add 
the recommended engine oil to the proper 
level.
2. Start the engine, warm it up for several  minutes, and then turn it off.
CAUTION:
ECA13410
When the engine is cold, the engine oil will 
have a higher viscosity, causing the engine 
oil pressure to increase. Therefore, be sure 
Oil filter wrench90890-01426
YU-38411
Oil filter cartridge17 Nm (1.7 m·kg, 12 ft·lb)
Engine oil drain bolt43 Nm (4.3 m·kg, 31 ft·lb)
Quantity Total amount
3.8 L (3.34 lmp qt, 4.02 US qt)
Without oil filter cartridge 
replacement 2.9 L (2.55 lmp qt, 3.07 US qt)
With oil filter cartridge replace-
ment 3.1 L (2.73 lmp qt, 3.28 US qt) 
						

							
ENGINE
3-14
to measure the engine oil pressure after 
warming up the engine.
3. Remove: Oil gallery bolt “1”
WARNING
EWA12980
The engine, muffler and engine oil are 
extremely hot.
4. Install: Oil pressure gauge “1”
 Adapter “2”
5. Measure:  Engine oil pressure(at the following conditions)
NOTE:
Regarding the oil pressure as its own data may 
fluctuate depending on the oil temperature and 
viscosity, the oil pressure may fluctuate when 
measuring. The followi ng data should be used 
only as a reference when measuring the 
engine oil pressure.
6. Install:  Oil gallery bolt “1”
CAUTION:
ECS2D1001
Be careful to tighten too much.
ET2D1004
ADJUSTING THE CLUTCH CABLE FREE 
PLAY
1. Check Clutch cable free play “a”
Out of specification  → Adjust.
Pressure gauge
90890-03153
YU-03153
Oil pressure adapter H 90890-03139
Engine oil pressure230 kPa
(2.3 kg/cm
2, 2.3 bar, 32.71 psi)
Engine speed Approx. 5,000 r/min
Engine oil temperature 100 °C (212 °F)
Engine oil pressure Possible causes
Below specification  Faulty oil pump  Clogged oil filter
 Leaking oil passage
 Broken or damaged oil seal
Above specification  Leaking oil passage  Faulty oil filter
 Oil viscosity too high
Oil gallery bolt8 Nm (0.8 m·kg, 5.8 ft·lb)
Clutch cable free play (at the 
end of the clutch lever)10–15 mm (0.39–0.59 in) 
						

							
ENGINE
3-15
2. Adjust Clutch cable free play
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
Handlebar side
a. Turn the adjusting dial “1” in direction “b” or  “c” until the specified clutch cable free play 
is obtained.
NOTE:
If the specified clutch cable free play cannot be 
obtained on the handlebar side of the cable, 
use the adjusting nut on the engine side.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
Engine side
a. Loosen the locknut “1”
b. Turn the adjusting nut “2” in direction “a” or 
“b” until the specified clutch cable free play 
is obtained.
c. Tighten the locknuts.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS20960
REPLACING THE AIR FILTER ELEMENT
1. Remove:  Rider and passenger seat
Refer to GENERAL CHASSIS on page 4-
1.
 Fuel tank
Refer to FUEL TANK on page 7-1.
2. Remove:  Air filter case cover “1”
3. Check:  Air filter element “1”Damage  → Replace.
NOTE:
 Replace the air filter element every 40000 
km (2400 mi) of operation.
 The air filter needs more frequent service if  you are riding in unusually wet or dusty 
areas.
Direction “b”
Clutch cable free play is increased.
Direction “c”
Clutch cable free play is decreased.
Direction “a” Clutch cable free play is increased.
Direction “b” Clutch cable free play is decreased.
Locknut
7 Nm (0.7 m·kg, 5.1 ft·lb)