Removing The Throttle Body; Checking The Fuel Injector; Checking The Throttle Body; Checking The Intake Manifold - Yamaha UMAX Service Manual

REMOVING THE THROTTLE BODY

1. Disconnect:
• Fuel hose
WARNING
Cover fuel hose connections with a cloth
when disconnecting them. Residual pres-
sure in the fuel lines could cause fuel to
spurt out when removing the hose.
NOTICE
• Be sure to disconnect the fuel hose by
hand. Do not forcefully disconnect the
hose with tools.
• Although the fuel has been removed from
the fuel tank, be careful when removing the
fuel hose, since there may be fuel remain-
ing in it.
TIP
• To disconnect the fuel hose from the fuel injec-
tor, slide the fuel hose connector cover "1" on
the end of the hose in the direction of the arrow
shown, press the two buttons "2" on the sides
of the connector, and then disconnect the
hose.
• Before disconnecting the hose, place a few
rags in the area under where it will be discon-
nected.

CHECKING THE FUEL INJECTOR

1. Check:
• Fuel injector
Obstruction → Replace and check the fuel
pump/fuel supply system.
Deposit → Replace.
Damage → Replace.
2. Check:
• Fuel injector resistance
Refer to "CHECKING THE FUEL INJEC-
TOR" on page 8-58.

CHECKING THE THROTTLE BODY

1. Check:
• Throttle body
Cracks/damage → Replace the throttle body.

CHECKING THE INTAKE MANIFOLD

1. Check:
• Intake manifold
Cracks/damage → Replace.
2. Check:
• Air passage
Obstructions → Clean.
a. Wash the intake manifold in a petroleum-
based solvent.
Do not use any caustic carburetor clean-
ing solution.
b. Blow out the passage with compressed
air.

CHECKING THE INTAKE MANIFOLD JOINT

1. Check:
• Intake manifold joint
Cracks/damage → Replace.

INSTALLING THE THROTTLE BODY

1. Install:
• Intake manifold joint "1"
TIP
Install the intake manifold joint so that the projec-
tion "a" on the joint is pointing outward.
1
2. Install:
• Intake air temperature sensor "1"
Intake air temperature sensor
screw
3.5 N·m (0.35 kgf·m, 2.6 lb·ft)
TIP
Make sure that the hose "2" between the intake
air temperature sensor and the intake manifold
is not kinked or bent.
6-6
THROTTLE BODY
a