1999 YAMAHA YZF-R7 fuel pressure

3 - 51
CHK
ADJ
CHECKING THE TIRES
EB304170
CHECKING THE TIRES
The following procedure applies to both of
the tires.
1. Measure:
• tire pressure
Out of specification ® Regulate.
WARNINGWARNING
• The tire pressure should only be
checked and regulated when the tire
temperature equals the ambient air
temperature.
• The tire pressure and the suspension
must be adjusted according to the
total weight (including cargo, rider,
passenger and accessories) and the
anticipated riding speed.
• Operation of an overloaded motorcy-
cle could cause tire damage, an acci-
dent or an injury.
NEVER OVERLOAD THE MOTORCYCLE.
* total of cargo, rider and accessories
WARNINGWARNING
It is dangerous to ride with a worn-out
tire. When the tire tread reaches the
wear limit, replace the tire immediately.Basic weight
(with oil
and a full
fuel tank)207 kg (456 lb)
Maximum
load*317 kg (699 lb)
Cold tire
pressureFront Rear
Up to 90 kg
(198 lb)
load*250 kPa
(2.5 kgf/cm
2,
36 psi)250 kPa
(2.5 kgf/cm2,
36 psi)
90 kg (198 lb)
~ maximum
load*250 kPa
(2.5 kgf/cm
2,
36 psi)290 kPa
(2.9 kgf/cm2,
41 psi)
High-speed
riding250 kPa
(2.5 kgf/cm
2,
36 psi)250 kPa
(2.5 kgf/cm2,
36 psi)

6 - 1
EFI

ELECTRONIC FUEL INJECTION
ELECTRONIC FUEL INJECTION
ELECTRONIC FUEL INJECTION
Order Job/Part Q’ty Remarks
Removing the injector 2 assembly
and air filter case
Remove the parts in the order listed.
Air filter case cover Refer to “FUEL TANK AND AIR FIL-
TER” in chapter 3.
1 Crankcase breather hose 1 Disconnect.
2 Fuel hose 3
3 Injector 2 sub-lead coupler 3 Disconnect.
4 Pressure sensor hose 2 Disconnect.
5 Plastic band 1
6 Injector 2 assembly 1
7 Spacer 6
8 Air funnel 4
9 Air funnel bracket 4
10 Fuel hose joint pipe 1
6

6 - 2
EFI

ELECTRONIC FUEL INJECTION
Order Job/Part Q’ty Remarks
11 Intake air temperature sensor 1
12 Copper washer 1
13 Air filter case breather hose 1 Disconnect.
14 Negative pressure hose 1 Disconnect.
15 Air funnel rubber seat 4
16 Air filter case 1
For installation, reverse the removal
procedure.
6

6 - 3
EFI

T R..30 Nm (3.0 m • kg, 22 ft • Ib)
T R..8 Nm (0.8 m • kg, 5.8 ft • Ib)
T R..5 Nm (0.5 m • kg, 3.6 ft • Ib)
T R..8 Nm (0.8 m • kg, 5.8 ft • Ib)
(4)
1
2
3
4
5 6
7
10
9 8
11
2012
14
11
12
13
15
19
16
18
17
LTLT
LTLT
LTLT

ELECTRONIC FUEL INJECTION
Order Job/Part Q’ty Remarks
Removing the injector 2
Remove the parts in the order listed.
1 Intake air pressure sensor coupler 1
2 Atmospheric pressure sensor cou-
pler1
3 Cylinder #1 – injector 2 coupler 1
4 Cylinder #2 – injector 2 coupler 1
5 Cylinder #3 – injector 2 coupler 1
6 Cylinder #4 – injector 2 coupler 1
7 Pressure sensor hose 2
8 Intake air pressure sensor 1
9 Atmospheric pressure sensor 1
10 Pressure sensor bracket 1
11 Union bolt 2
12 Washer 4

6 - 7
EFI

ELECTRONIC FUEL INJECTION
Order Job/Part Q’ty Remarks
Removing the injector 1 and throttle
body
Remove the parts in the order listed.
1 Negative pressure hose 1
2 Pressure regulator 1
3 Union bolt 1
4 Washer 2
5 Injector fuel pipe 1 1
6 Injector fuel pipe 2 1
7 Washer 1
8 Fuel distributor 1
9 Injector 1 4
10 O-ring 4
11 Seal 4
12 Seal 4
13 Rear connecting plate 1

6 - 10
EFI

ELECTRONIC FUEL INJECTION
CHECKING THE PRESSURE REGULATOR
1. Check:
• pressure regulator
Damage
®
Replace.
EAS00502
CHECKING AND ADJUSTING THE
THROTTLE POSITION SENSOR
NOTE:

Before adjusting the throttle position
sensor, the engine idling speed should
be properly adjusted.
1. Check:
• throttle position sensor
(installed on the throttle body)
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. Disconnect the throttle position sen-
sor coupler from the throttle position
sensor.
b. Connect the pocket tester (
W

´
1k) to
the throttle position sensor.
c. Measure the maximum throttle posi-
tion sensor resistance.
Out of specification
®
Replace the
throttle position sensor.
Positive tester probe
®

blue terminal
1
Negative tester probe
®

black/blue terminal
2
Maximum throttle position
sensor resistance
4.0 ~ 6.0 k
W
at 20 ˚C (68 ˚F)
(blue — black/blue)
B/LYL
231

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)

6 - 15
EFIELECTRONIC FUEL INJECTION
i. Use the mity vac to adjust the fuel
pressure in relation to the vacuum
pressure as described below.
NOTE:
The vacuum pressure should not exceed
100 kPa (1 mmHg, 0.04 in. Hg).
Faulty ® Replace the pressure regula-
tor.
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
Increase the vacuum pressure. ®
Fuel pressure is decreased.
Decrease the vacuum pressure. ®
Fuel pressure is increased.