Yamaha Fz6n Manual

							3-24
CHECKING THE SPARK PLUGS /
MEASURING THE COMPRESSION PRESSURECHK
ADJ
18 Nm (1.8 m
kg, 13 ft
lb)
NOTE:
NOTE: 7. Install:

spark plug

spark plug caps
Before installing the spark plug, clean the spark
plug and gasket surface.
8. Install:

radiator lower hose bracket bolt

radiator lower bolt
EAS00065
MEASURING THE COMPRESSION 
PRESSURE
The following procedure applies to all of the cyl-
inders.
Insufficient compression pressure will result in a
loss of performance.
1. Measure:

valve clearance
Out of specification 
 Adjust.
Refer to “ADJUSTING THE VALVE CLEAR-
ANCE”.
2. Start the engine, warm it up for several min-
utes, and then turn it off.
3. Remove:

rider seat
Refer to “SEAT”.

front cowling inner panel (letf and right)
Refer to “COWLINGS”.

fuel tank
Refer to “FUEL TANK”.

air filter case
Refer to “AIR FILTER CASE”.

battery
Refer to “CHECKING AND CHARGING THE
BATTERY” in chapter 3.

battery box

battery box bracket
Refer to “BATTERY BOX AND BATTERY
BOX BRACKET”.

heat protector plate
4. Remove:

cover

ignition coils

spark plug caps

spark plugs 
						

							3-25
MEASURING THE COMPRESSION PRESSURE
CHK
ADJ
CAUTION:
WARNING
NOTE: 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.
5. Install:

compression gauge 
1

adapter
Compression gauge
90890-03081, YU-33223
Adapter
90890-04136
6. Measure:

compression pressure
Out of specification 
 Refer to steps (c) and
(d).
Compression pressure 
(at sea level)
Minimum
1,350 kPa (13.50 kg / cm
2,
13.50 bar, 191.87 psi)
Standard
1,550 kPa (15.50 kg / cm
2,
15.50 bar, 220.46 psi)
Maximum
1,736 kPa (17.36 kg / cm
2,
17.36 bar, 246.92 psi)
a. Turn the main switch to “ON”.
b. With the throttle wide open, crank the engine
until the reading on the compression gauge
stabilizes.
To prevent sparking, ground all spark plug
leads before cranking the engine.
The difference in compression pressure be-
tween cylinders should not exceed 100 kPa (1
kg/cm
2, 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. 
						

							3-26
MEASURING THE COMPRESSION PRESSURE
CHK
ADJ
18 Nm (1.8 m
kg, 13 ft
lb)
d. If the compression pressure is below the
minimum specification, pour a teaspoonful of
engine oil into the spark plug bore and mea-
sure again.
Refer to the following table.
Compression pressure
(with oil applied into the cylinder)
ReadingDiagnosis
Higher than
without oilPiston ring(s) wear
or damage 
 
Repair.
Same as without
oilPiston, valves,
cylinder head 
gasket or piston 
possibly defective 

 Repair.
7. Install:

spark plug
8. Install:

spark plug caps

ignition coils
9. Install:

heat protector plate

battery box bracket

battery box
Refer to “BATTERY BOX AND BATTERY
BOX BRACKET”.

battery
Refer to “CHECKING AND CHARGING THE
BATTERY” in chapter 3.

air filter case
Refer to “AIR FILTER CASE”.

fuel tank
Refer to “FUEL TANK”.

front cowling inner panel (letf and right)
Refer to “COWLINGS”.

rider seat
Refer to “SEAT”. 
						

							3-27
CHECKING THE ENGINE OIL LEVEL
CHK
ADJ
NOTE:
EAS00069
CHECKING THE ENGINE OIL LEVEL
1. Stand the motorcycle on a level surface.

Place the motorcycle on a suitable stand.

Make sure the motorcycle is upright.
2. Start the engine, warm it up for several min-
utes, and then turn it off.
3. Check:

engine oil level
The 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.
Recommended oil
AT  5C (40F) or higher 
A
Yamalube 4 (20W40) or
SAE 20W40 type SE motor
oil
AT  1 5C (60F) or lower 
B
Yamalube 4 (10W30) or
SAE 10W30 type SE motor
oil 
						

							3-28
CHECKING THE ENGINE OIL LEVEL /
CHANGING THE ENGINE OILCHK
ADJ
NOTE:
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 min-
utes, and then turn it off.
5. Check the engine oil level again.
Before checking the engine oil level, wait a few
minutes until the oil has settled.
EAS00074
CHANGING THE ENGINE OIL
1. Start the engine, warm it up for several min-
utes, 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) 
						

							3-29
CHANGING THE ENGINE OIL
CHK
ADJ
CAUTION:
43 Nm (4.3 m
kg, 31 ft
lb)
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.
Oil filter wrench
90890-01426, YU-38411
b. Lubricate the O-ring 
3 of the new oil filter
cartridge with a thin coat of engine oil.
Make sure the O-ring 
3 is positioned cor-
rectly in the groove of the oil filter cartridge.
c. Tighten the new oil filter cartridge to specifi-
cation with an oil filter wrench.
Oil filter cartridge
17 Nm (1.7 m
kg, 12 ft
lb)
6. Replace:

engine oil drain bolt gasket 
New
7. Install:

engine oil drain bolt
(along with the new gasket)
8. Fill:

crankcase
(with the specified amount of the recom-
mended engine oil)
Quantity
Total amount
3.4 L (2.99 Imp qt, 3.59 US qt)
Without oil filter cartridge
replacement
2.5 L (2.20 Imp qt, 2.64 US qt)
With oil filter cartridge
replacement
2.8 L (2.47 Imp qt, 2.96 US qt) 
						

							3-30
CHANGING THE ENGINE OIL /
MEASURING THE ENGINE OIL PRESSURECHK
ADJ
CAUTION:
WARNING
9. Install:

engine oil filler cap
10. Start the engine, warm it up for several min-
utes, and then turn it off.
11. Check:

engine (for engine oil leaks)
12. Check:

engine oil level
Refer to “CHECKING THE ENGINE OIL
LEVEL”.
EAS00077
MEASURING THE ENGINE OIL PRESSURE
1. Check:

engine oil level
Below the minimum level mark 
 Add the
recommended engine oil to the proper level.
2. Start the engine, warm it up for several min-
utes, and then turn it off.
When the engine is cold, the engine oil will
have a higher viscosity, causing the engine
oil pressure to increase. Therefore, be sure
to measure the engine oil pressure after
warming up the engine.
3. Remove:

oil gallery bolt 
1
The engine, muffler and engine oil are ex-
tremely hot.
4. Install:

oil pressure gauge 
1

adapter 2
Pressure gauge
90890-03153, YU-03153
Oil pressure adapter
90890-03139 
						

							3-31
MEASURING THE ENGINE OIL PRESSURE
CHK
ADJ
NOTE:
8 Nm (0.8 m
kg, 5.8 ft
lb)
5. Measure:

engine oil pressure
(at the following conditions)
Engine oil pressure
240 kPa
(2.4 kg / cm
2, 2.4 bar, 34.1 psi)
Engine speed
Approx. 6,600 r / min
Engine oil temperature
96C (205F)
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 following data should be used
only as a reference when measuring the engine
oil pressure.
Engine oil pressure
Possible causes
Below 
ifi i
Faulty oil pump
specificationClogged oil filter
Leaking oil 
passage
Broken or 
damaged oil seal
Above 
specificationLeaking oil 
passage
Faulty oil filter
Oil viscosity too 
high
6. Install:

oil gallery bolt 
1 
						

							3-32
ADJUSTING THE CLUTCH CABLE FREE PLAY
CHK
ADJ
c
b
NOTE:
a
b
EAS00078
ADJUSTING THE CLUTCH CABLE FREE 
PLAY
1. Check:

clutch cable free play 
a
Out of specification 
 Adjust.
Clutch cable free play (at the 
end of the clutch lever)
10  15 mm (0.39  0.59 in)
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 ob-
tained.
Direction
Clutch cable free play is
increased.
DirectionClutch cable free play is
decreased.
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
3. Remove:

seat
Refer to “SEAT”.

front cowling inner panel (left and right)
Refer to “COWLINGS”.

fuel tank
Refer to “FUEL TANK”.

air filter case
Refer to “AIR FILTER CASE”.
a. Loosen the locknuts 
1.
b. Turn the adjusting nut 
2 in direction a or b
until the specified clutch cable free play is ob-
tained.
Direction
Clutch cable free play is
increased.
DirectionClutch cable free play is
decreased.
d. Tighten the locknuts. 
						

							3-33
ADJUSTING THE CLUTCH CABLE FREE PLAY /
CLEANING THE AIR FILTER ELEMENTCHK
ADJ
CAUTION:
4. Install:

air filter case
Refer to “AIR FILTER CASE”.

fuel tank
Refer to “FUEL TANK”.

front cowling inner panel (left and right)
Refer to “COWLINGS”.

seat
Refer to “SEAT”.
EAS00086
CLEANING THE AIR FILTER ELEMENT
1. Remove:

rider seat
Refer to “SEAT”.

front cowling inner panel (left and right)
Refer to “COWLINGS”.

fuel tank
Refer to “FUEL TANK”.
2. Remove:

air filter case cover 
1

air filter element 2
3. Clean:

air filter element 
2
4. Check:

air filter element
Damage 
 Replace.
5. Install:

air filter element 
2

air filter case cover 1
Never operate the engine without the air fil-
ter element installed. Unfiltered air will
cause rapid wear of engine parts and may
damage the engine. Operating the engine
without the air filter element will also affect
the throttle bodies tuning, leading to poor
engine performance and possible overheat-
ing.