engine YAMAHA YZF-R7 1999 Service Manual

3 - 15
CHK
ADJ
SYNCHRONIZING THE THROTTLE BODIES
4. Install:
• vacuum gauge attachments
(into the bolt holes)
• vacuum gauge
(onto the vacuum gauge attachments)
• engine tachometer
(onto the ignition coil of cylinder #1)
NOTE:
Disconnect the ignition coil coupler and
remove the ignition coil 1 of cylinder
#1, remove the rubber cover 2, and
wrap the engine tachometer lead sev-
eral times around section a of the igni-
tion coil. Then, install the ignition coil
and connect the ignition coil coupler.
5. Install:
• fuel tank
Refer to “FUEL TANK AND AIR FIL-
TER”.
6. Start the engine and let it warm up for
several minutes.
Vacuum gauge
90890-03094
Vacuum gauge attachment
90890-03060
Engine tachometer
90890-06760
1 1
2
2
a
a
7. Measure:
• engine idling speed
Out of specification ® Adjust.
Refer to “ADJUSTING THE ENGINE
IDLING SPEED”.
Engine idling speed
1,000 ~ 1,200 r/min
8. Adjust:
• throttle body synchronization
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. Turn the air screws 1 to adjust the
vacuum pressure of all throttle bodies
to specification.
NOTE:
Do not turn the synchronizing screws.1 11 1

3 - 16
CHK
ADJSYNCHRONIZING THE THROTTLE BODIES/
ADJUSTING THE ENGINE IDLING SPEED
NOTE:
The difference in vacuum pressure
between two throttle bodies should not
exceed 1.33 kPa (10 mm Hg, 0.4 in Hg).
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
9. Measure:
• engine idling speed
Out of specification ® Adjust.
10.Stop the engine and remove the mea-
suring equipment.
11.Adjust:
• throttle cable free play
Refer to “ADJUSTING THE THROTTLE
CABLE FREE PLAY”.
Vacuum pressure at engine
idling speed
15.8 ~ 18.4 kPa (120 ~ 140
mm Hg, 4.72 ~ 5.51 in Hg)
Throttle cable free play
(at the flange of the throttle
grip)
3 ~ 5 mm (0.12 ~ 0.20 in)
ADJUSTING THE ENGINE IDLING SPEED
NOTE:
Prior to adjusting the engine idling
speed, the throttle body synchronization
should be adjusted properly, the air filter
element should be clean, and the engine
should have adequate compression.
1. Start the engine and let it warm up for
several minutes.
2. Remove:
• bottom cowling
• front cowling
Refer to “COWLINGS”.

3 - 17
CHK
ADJADJUSTING THE ENGINE IDLING SPEED/
ADJUSTING THE THROTTLE CABLE FREE PLAY
3. Install:
• engine tachometer
(onto the ignition coil of cylinder #1)
NOTE:
Refer to “SYNCHRONIZING THE THROT-
TLE BODIES” for the engine tachometer
installation.
4. Measure:
• engine idling speed
Out of specification ® Adjust.
Engine tachometer
90890-06760
Engine idling speed
1,000 ~ 1,200 r/min
5. Adjust:
• engine idling speed
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. Turn the throttle stop screw 1 in
direction a or b until the specified
engine idling speed is obtained.
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
6. Adjust:
• throttle cable free play
Refer to “ADJUSTING THE THROTTLE
CABLE FREE PLAY”. Direction aEngine idling speed is
increased.
Direction bEngine idling speed is
decreased.
Throttle cable free play
(at the flange of the throttle
grip)
3 ~ 5 mm (0.12 ~ 0.20 in)
a a b b
1
1
EB303031
ADJUSTING THE THROTTLE CABLE FREE
PLAY
NOTE:
Prior to adjusting the throttle cable free
play, the engine idling speed and throt-
tle body synchronization should be
adjusted properly.

3 - 19
CHK
ADJADJUSTING THE THROTTLE CABLE FREE PLAY/
CHECKING THE SPARK PLUGS
Handlebar side
a. Loosen the locknut 4.
b. Turn the adjusting nut 5 in direction
c or d until the specified throttle
cable free play is obtained.
c. Tighten the locknut.
WARNINGWARNING
After adjusting the throttle cable free
play, start the engine and turn the han-
dlebars to the right and to the left to
ensure that this does not cause the
engine idling speed to change.
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
Direction cThrottle cable free play
is increased.
Direction dThrottle cable free play
is decreased.
C C
d d
7
7
5
57
7
4
4
EB303040
CHECKING THE SPARK PLUGS
The following procedure applies to all of
the spark plugs.
1. Remove:
• fuel tank
• air filter case cover
Refer to “FUEL TANK AND AIR FIL-
TER”.
• air filter case
Refer to “ELECTRONIC FUEL INJEC-
TION” in chapter 6.
2. Disconnect:
• ignition coil couplers
3. Remove:
• ignition coils
• spark plug
ACHTUNG:CAUTION:
Before removing the spark plugs, blow
away any dirt accumulated in the spark
plug wells with compressed air to pre-
vent it from falling into the cylinders.
4. Check:
• spark plug type
Incorrect ® Change.
Spark plugs
Model (manufacturer)
R0256R-10 (NGK)

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