check engine YAMAHA YZF-R7 1999 Service Manual

6 - 14
EFIELECTRONIC FUEL INJECTION
CHECKING THE FUEL PUMP AND
PRESSURE REGULATOR OPERATION
1. Check:
• pressure regulator operation
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 fuel tank and air filter
case cover.
Refer to “FUEL TANK AND AIR FIL-
TER” in chapter 3.
b. Disconnect the nagative pressure
hose 1 from the pressure regulator
at the joint.
c. Disconnect the injector fuel pipe 3 2
from the fuel distributor.
d. Connect the mity vac 3 onto the neg-
ative pressure hose from the pressure
regulator.
e. Install the pressure gauge 4 and
adapter 5 with the washers and
injector fuel pipe 3 onto the fuel dis-
tributor.
f. Install the fuel tank.
Refer to “FUEL TANK AND AIR FIL-
TER” in chapter 3.
g. Start the engine.
h. Measure the fuel pressure.
Mity vac
90890-06756
Pressure gauge
90890-03153
Adapter
90890-03151
T R..
Adapter
30 Nm (3.0 m • kg, 22 ft • lb)
Fuel pressure
250 ~ 260 kPa
(2.5 ~ 2.6 kgf/cm
2,
35.6 ~ 37.0 psi)

7 - 85
CHAS
c. Remove the drive chain from the ker-
osine and completely dry it.
ACHTUNG:CAUTION:
This motorcycle has a drive chain with
small rubber O-rings 1 between the
drive chain side plates. Never use high-
pressure water or air, steam, gasoline,
certain solvents (e.g., benzine), or a
coarse brush to clean the drive chain.
High-pressure methods could force dirt
or water into the drive chain’s internals,
and solvents will deteriorate the O-
rings. A coarse brush can also damage
the O-rings. Therefore, use only kero-
sine to clean the drive chain.
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
4. Check:
• O-rings 1
Damage ® Replace the drive chain.
• drive chain rollers 2
Damage/wear ® Replace the drive
chain.
• drive chain side plates 3
Cracks/damage/wear ® Replace the
drive chain.
5. Lubricate:
• drive chain
Recommended lubricant
Engine oil or chain lubricant
suitable for O-ring chains
6. Check:
• drive sprocket
• rear wheel sprocket
More than 1/4 tooth a wear ® Replace
the drive chain sprockets as a set.
Bent teeth ® Replace the drive chain
sprockets as a set.
b Correct
1Drive chain roller
2Drive chain sprocket
SWINGARM AND DRIVE CHAIN

8 - 2
–+ELEC

SWITCHES
EB801000
SWITCHES
CHECKING SWITCH CONTINUITY
Check each switch for continuity with the
pocket tester. If the continuity reading is
incorrect, check the wiring connections and
if necessary, replace the switch.
CAUTION:

Never insert the tester probes into the cou-
pler terminal slots
1
. Always insert the
probes from the opposite end of the cou-
pler, taking care not to loosen or damage
the leads.
NOTE:

• Before checking for continuity, set the
pocket tester to “0” and to the “
W

´
1”
range.
• When checking for continuity, switch back
and forth between the switch positions a
few times.
The terminal connections for switches (e.g.,
main switch, engine stop switch) are shown
in an illustration similar to the one on the
left.
The switch positions
a
are shown in the far
left column and the switch lead colors
b
are shown in the top row in the switch illus-
tration.
NOTE:

“ ” indicates a continuity of electric-
ity between switch terminals (i.e., a closed
circuit at the respective switch position).
The example illustration on the left shows
that:
There is continuity between blue/red and
red when the switch is set to “ ”.
There is continuity between blue/red and
blue, between brown/blue and red, and
between blue/yellow and blue/black when
the switch is set to “ON”.
Pocket tester
90890-03112
ONR
Br/LL/YL/B
OFF
ab
Br/L
L/B R
L/Y

8

8 - 3
–+ELEC

CHECKING THE SWITCHES
EB801010
CHECKING THE SWITCHES
Check each switch for damage or wear, proper connections, and also for continuity between
the terminals. Refer to “CHECKING SWITCH CONTINUITY”.
Damage/wear
® Repair or replace the switch.
Improperly connected ® Properly connect.
Incorrect continuity reading ® Replace the switch.
1Main switch
2Light switch
3Pass switch
4Dimmer switch
5Turn signal switch6Horn switch
7Clutch switch
8Engine stop switch
9Start switch
0Front brake light switchAOil level switch
BRear brake light switch
CFuse
DNeutral switch
ESidestand switch
1L/YL/B
LL/R
R
Br/L
OFF
ONP
L/RLBr/LRL/YL/B
3
4
5
Br/WR/YPLB
Dg Y
G Ch
B/YL/YPASS—
R/YY
67
YG
—BP
(BLUE)
(BLACK)
(BLACK)
R/WBr
R/BB
G/YL/W
B
B
G/YBr
OFF
ChBr/WDg
8R/WR/B
9
0—L/WB
2R/YL•
C
E
(BLUE)
B
B
B D
(BROWN)
Sb
A
W
L/YB/Y
L/YB/Y

8 - 8
–+ELECIGNITION SYSTEM
TROUBLESHOOTING
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
No good
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK The ignition system fails to operate (no spark or intermittent spark).
Check the main and ECU fuses for
continuity.Replace.
Check the condition of the bat-
tery.Recharge or replace.
Check the spark plug. Re-gap or replace.
Measure the ignition spark gap. Ignition system is OK.
Measure the ignition coil resis-
tance.Replace.
Measure the pickup coil resis-
tance.Replace.
Check the main switch. Replace.
Check the engine stop switch.Replace the right handlebar
switch.
Check the neutral switch. Replace.
Check the diode. Replace.
Check the sidestand switch. Replace.
Check the relay unit. Replace.
Check the entire ignition sys-
tem’s wiring.Repair or replace.
Replace the CDI unit.
No good
No good
No good
No good
No good
No good
No good
No good
No good
OK
No good
No good
No good

8 - 9
–+ELECIGNITION SYSTEM
BAD
NOTE:
• Before troubleshooting, remove the following part(-s):
1) fuel tank
2) air filter case
3) bottom cowling
4) front cowling
5) rear cowling
• Troubleshoot with the following special tool(-s).
Replace the ECU.
Ignition checker
90890-06754
Pocket tester
90890-03112
MEASURING THE IGNITION SPARK GAP
The following procedure applies to all of
the spark plugs.
• Disconnect the ignition coil from the spark
plug.
• Connect the ignition checker 1 as shown.
2 Ignition coil
• Set the main switch to “ON”.
• Measure the ignition spark gap a.
• Crank the engine by pushing the start
switch and gradually increase the spark
gap until a misfire occurs.
• Is there a spark and is the spark gap
within specification?
Yes ® Good.
No ® Measure the ignition coil resistance.
Minimum ignition spark gap
6 mm (0.24 in)

8 - 13
–+ELECELECTRIC STARTING SYSTEM
TROUBLESHOOTING
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK The starter motor fails to turn.
Check the main and ECU fuses for
continuity.Replace.
Check the condition of the bat-
tery.Recharge or replace.
Check the starter motor. Repair or replace.
Check the relay unit. Replace.
Check the starter relay. Replace.
Check the diodes. Replace.
Check the main switch. Replace.
Check the engine stop switch.Replace the right handlebar
switch.
Check the neutral switch. Replace.
Check the sidestand switch. Replace.
Check the clutch switch. Replace.
Check the start switch.Replace the right handlebar
switch.
Check the entire starting sys-
tem’s wiring.Repair or replace.
No good
No good
No good
No good
No good
No good
No good
No good
No good
No good
No good
No good
No good

8 - 17
–+ELECCHARGING SYSTEM
TROUBLESHOOTING
C0NTINUITYOK
C0NTINUITYOK
No good
C0NTINUITYOK
C0NTINUITYOK
NOTE:
• Before troubleshooting, remove the following part(-s):
1) bottom cowling
2) front cowling
3) rear cowling
• Troubleshoot with the following special tool(-s).
The battery is not being charged.
Check the main fuse for continu-
ity.Replace.
Check the condition of the bat-
tery.Recharge or replace.
Measure the charging voltage. The charging circuit is OK.
Measure the stator coil assembly
resistance.Replace.
Check the entire charging sys-
tem’s wiring.Repair or replace.
Replace the rectifier/regulator.
Engine tachometer
90890-06760
Pocket tester
90890-03112
No good
No good
No good
No good
ON

8 - 23
–+ELECSIGNALING SYSTEM
NOTE:
• Before troubleshooting, remove the following part(-s):
1) fuel tank
2) bottom cowling
3) front cowling
4) rear cowling
• Troubleshoot with the following special tool(-s).
Pocket tester
90890-03112
CHECKING THE RELAY UNIT
• Remove the relay unit from the coupler.
• Connect the pocket tester (W ´ 1) to the
relay unit terminals as shown.
• Check the starting circuit cutoff relay for
continuity.
NOTE:
When you switch the tester’s positive and
negative probes, the readings in the above
chart will be reversed.
• Are the tester readings correct?
Yes ® Good.
No ® Replace.
CHECKING THE OIL LEVEL SWITCH
• Drain the engine oil.
• Remove the oil level switch.
• Connect the pocket tester (W ´ 1) to the oil
level switch connector as shown.
• Check the oil level switch for continuity as
follows.
• Are the oil level switch readings correct?
Yes ® Good.
No ® Replace. Tester positive probe ®
sky blue 1
Tester negative probe ®
blue/red 2Continu-
ity
Tester positive probe ®
blue/red 2
Tester negative probe ®
sky blue 1No conti-
nuity
Tester positive probe ® white 1
Tester negative probe ® ground
Oil level switch float posi-
tion is upper .Continu-
ity
Oil level switch float posi-
tion is lower õ.No conti-
nuity
R/B L/WW G
Lg
L/R L/BSbB/Y B B/R L/Y
1 2
W
W
õ
11

8 - 25
–+ELECCOOLING SYSTEM
TROUBLESHOOTING
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
C0NTINUITYOK
NOTE:
• Before troubleshooting, remove the following part(-s):
1) bottom cowling
2) front cowling
3) rear cowling
• Troubleshoot with the following special tool(-s).
• The radiator fan motor fails to turn.
• The coolant temperature meter needle fails to move when the engine is warm.
Check the main and radiator fan
motor fuses for continuity.Replace.
Check the condition of the bat-
tery.Recharge or replace.
Check the main switch. Replace.
Check the radiator fan motor. Replace.
Check the thermo switch. Replace.
Check the entire cooling system’s
wiring.Repair or replace.
Pocket tester
90890-03112
No good
No good
No good
No good
No good
No good