1999 YAMAHA YZF-R7 Owners Manual

3 - 20
CHK
ADJCHECKING THE SPARK PLUGS/
MEASURING THE COMPRESSION PRESSURE
5. Check:
• electrodes 1
Damage/wear ® Replace the spark
plug.
• insulator 2
Abnormal color ® Replace the spark
plug.
Normal color is medium-to-light tan.
6. Clean:
• spark plug
(with a spark plug cleaner or wire
brush)
7. Measure:
• spark plug gap a
(with a wire gauge)
Out of specification ® Regap.
8. Install:
• spark plug
NOTE:
Before installing the spark plug, clean
the spark plug and gasket surface.
Spark plug gap
0.7 ~ 0.8 mm (0.028 ~ 0.031 in)
T R..13 Nm (1.3 m · kg, 9.4 ft · lb)
EB303060
MEASURING THE COMPRESSION
PRESSURE
The following procedure applies to all of
the cylinders.
NOTE:
Insufficient compression pressure will
result in a loss of performance.
1. Measure:
• valve clearance
Out of specification ® Adjust.
Refer to “ADJUSTING THE VALVE
CLEARANCE”.
2. Start the engine, warm it up for several
minutes, and then stop it.

3 - 21
CHK
ADJ
MEASURING THE COMPRESSION PRESSURE
3. Remove:
• fuel tank
• air filter case cover
Refer to “FUEL TANK AND AIR FIL-
TER”.
• air filter case
• throttle body assembly
Refer to “ELECTRONIC FUEL INJEC-
TION” in chapter 6.
• ignition coil
4. Remove:
• spark plug
ACHTUNG:CAUTION:
Before removing the spark plugs, use
compressed air to blow away any dirt
accumulated in the spark plug wells to
prevent it from falling into the cylinders.
5. Install:
• compression gauge 1
• adapter 2
Compression gauge
90890-03081
Adapter
90890-04136
1
1

2

2

6. Measure:
• compression pressure
Out of specification ® Refer to steps
(c) and (d).
t t t t t t t t t t t t t t t t t t t t t t t t t t t
a. Set the main switch to “ON”.
b. With the throttle wide open, crank the
engine until the reading on the com-
pression gauge stabilizes.
Compression pressure (at sea
level)
Minimum
1,500 kPa
(15.0 kg/cm
2, 213 psi)
Standard
1,600 kPa
(16.0 kg/cm
2, 228 psi)
Maximum
1,700 kPa
(17.0 kg/cm
2, 242 psi)

3 - 22
CHK
ADJ
MEASURING THE COMPRESSION PRESSURE
WARNINGWARNING
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, 14 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, squirt a
few drops of oil into the cylinder and
measure again.
Refer to the following table.
s s s s s s s s s s s s s s s s s s s s s s s s s s s
7. Install:
• spark plug Compression pressure
(with oil applied into the cylinder)
Reading Diagnosis
Higher than with-
out oilPiston wear or
damage ® Repair.
Same as without
oilPiston ring(-s),
valve(-s), cylinder
head gasket or
piston possibly
defective ®
Repair.
T R..13 Nm (1.3 m · kg, 9.4 ft · lb)

3 - 23
CHK
ADJ
CHECKING THE ENGINE OIL LEVEL
EB303070
CHECKING THE ENGINE OIL LEVEL
1. Stand the motorcycle on a level surface.
NOTE:
• Place the motorcycle on a suitable stand.
• Make sure that the motorcycle is
upright.
2. Start the engine, let it idle for several
minutes, and then stop it.
3. Check:
• engine oil level
The engine oil level should be between
the minimum level mark a and maxi-
mum level mark b.
Below the minimum level mark ® Add
the recommended engine oil to the
proper level.
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
(Non-Friction modified)
ACHTUNG:CAUTION:
• Engine oil also lubricates the clutch
and the wrong oil types or additives
could cause clutch slippage. There-
fore, do not add any chemical addi-
tives or use engine oils with a grade of
CD c or higher and do not use oils
labeled “ENERGY CONSERVING II” d
or higher.
• Do not allow foreign materials to
enter the crankcase.
4. Start the engine, warm it up for several
minutes, and then turn it off.
5. Check:
• engine oil level
NOTE:
Before checking the engine oil level,
wait a few minutes until the oil has set-
tled.

3 - 24
CHK
ADJ
CHANGING THE ENGINE OIL
EB303081
CHANGING THE ENGINE OIL
1. Remove:
• bottom cowling
• front cowling
Refer to “COWLINGS”.
2. Start the engine, warm it up for several
minutes, and then turn it off.
3. Place a container under the engine oil
drain bolt.
4. Remove:
• engine oil filler cap 1
• engine oil drain bolt 2
(along with the washer)
5. Drain:
• engine oil
(completely from the crankcase)
1
1

6. If the oil filter cartridge is also to be
replaced, perform the following proce-
dure.
t t t t t t t t t t t t t t t t t t t t t t t t t t t
a. Remove the oil filter cartridge 1 with
an oil filter wrench 2.
Oil filter wrench
90890-01426
b. Lubricate the O-ring 3 of the new oil
filter cartridge with a thin coat of
engine oil.
ACHTUNG:CAUTION:
Make sure that the O-ring 3 is posi-
tioned correctly in the groove of the oil
filter cartridge.
c. Tighten the new oil filter cartridge to
specification with an oil filter wrench.
s s s s s s s s s s s s s s s s s s s s s s s s s s s
7. Check:
• engine oil drain bolt washer
Damage ® Replace.
8. Install:
• engine oil drain bolt
T R..
Oil filter cartridge
17 Nm (1.7 m • kg, 12 ft • lb)
T R..43 Nm (4.3 m · kg, 31 ft • lb)

3 - 25
CHK
ADJ
CHANGING THE ENGINE OIL
9. Fill:
• crankcase
(with the specified amount of the rec-
ommended engine oil)
10.Install:
• engine oil filler cap
11.Start the engine, warm it up for several
minutes, and then turn it off.
12.Check:
• engine
(for engine oil leaks)
13.Check:
• engine oil level
Refer to “CHECKING THE ENGINE OIL
LEVEL”.
Quantity
Total amount
3.6 L (3.2 lmp qt, 3.8 US qt)
Without oil filter cartridge
replacement
2.6 L (2.3 lmp qt, 2.7 US qt)
With oil filter cartridge
replacement
2.8 L (2.5 lmp qt, 3.0 US qt)
14.Check:
• engine oil pressure
t t t t t t t t t t t t t t t t t t t t t t t t t t t
a. Slightly loosen the oil gallery bolt 1.
b. Start the engine and keep it idling
until engine oil starts to seep from the
oil gallery bolt. If no engine oil comes
out after one minute, turn the engine
off so that it will not seize.
c. Check the engine oil passages, the oil
filter cartridge and the oil pump for
damage or leakage. Refer to “OIL
PAN AND OIL PUMP” in chapter 4.
d. Start the engine after solving the
problem(-s) and check the engine oil
pressure again.
e. Tighten the oil gallery bolt to
specification.
s s s s s s s s s s s s s s s s s s s s s s s s s s s
T R..
Oil gallery bolt
20 Nm (2.0 m • kg, 14 ft • lb)
1
1

3 - 26
CHK
ADJCHANGING THE ENGINE OIL/
CHECKING THE CLUTCH FLUID LEVEL
15.Install:
• front cowling
• bottom cowling
Refer to “COWLINGS”.
EB303100
CHECKING THE CLUTCH FLUID LEVEL
1. Stand the motorcycle on a level surface.
NOTE:
• Place the motorcycle on a suitable
stand.
• Make sure that the motorcycle is
upright.
2. Check:
• clutch fluid level
Below the minimum level mark a ®
Add the recommended clutch fluid to
the proper level.
WARNINGWARNING
• Use only the designated clutch fluid.
Other fluids may cause the rubber
seals to deteriorate, causing leakage
and poor clutch performance.
• Refill with the same type of fluid. Mix-
ing fluids may result in a harmful
chemical reaction leading to poor
clutch performance.
• When refilling, be careful that water
does not enter the clutch fluid reser-
voir. Water will significantly lower the
boiling point of the fluid and could
cause vapor lock.
ACHTUNG:CAUTION:
Clutch fluid may damage painted sur-
faces and plastic parts. Always clean up
any split fluid immediately.
NOTE:
In order to ensure a correct reading of
the clutch fluid level, make sure that the
top of the clutch fluid reservoir is hori-
zontal.
Recommended clutch fluid
Brake fluid DOT 4aa

3 - 27
CHK
ADJ
BLEEDING THE HYDRAULIC CLUTCH
SYSTEM
WARNINGWARNING
Bleed the hydraulic clutch system
whenever:
• the clutch system was disassembled,
• a clutch hose was loosened, discon-
nected or replaced,
• the clutch fluid level is very low,
• clutch operation is faulty.
NOTE:
• Be careful not to spill any clutch fluid
or allow the clutch fluid reservoir to
overflow.
• When bleeding the hydraulic clutch
system, make sure that there is always
enough clutch fluid before applying
the clutch. Ignoring this precaution
could allow air to enter the hydraulic
clutch system, considerably lengthen-
ing the bleeding procedure.
• If bleeding is difficult, it may be neces-
sary to let the clutch fluid settle for a
few hours. Repeat the bleeding proce-
dure when the tiny bubbles in the hose
have disappeared.
1. Bleed:
• hydraulic clutch system
t t t t t t t t t t t t t t t t t t t t t t t t t t t
a. Fill the clutch fluid reservoir to the
proper level with the recommended
clutch fluid.
b. Install the clutch fluid reservoir dia-
phragm.
c. Connect a clear plastic hose 1 tightly
to the bleed screw 2.
d. Place the other end of the hose into a
container.
e. Slowly apply the clutch several times.
f. Fully squeeze the clutch lever and
hold it in position.
g. Loosen the bleed screw.
NOTE:
Loosening the bleed screw will release
the pressure and cause the clutch lever
to contact the grip.
h. Tighten the bleed screw and then
release the clutch lever.
i. Repeat steps (e) to (h) until all of the
air bubbles have disappeared from
the clutch fluid in the plastic hose.
2
2
1
1

BLEEDING THE HYDRAULIC CLUTCH SYSTEM