height YAMAHA WR 400F 2002 User Guide

4 - 13
ENGCARBURETOR
EC464511
Float height
1. Measure:
Float height a
Out of specification → Adjust.
Float height:
8.0 mm (0.31 in)
Measurement and adjustment steps:
Hold the carburetor in an upside down
position.
NOTE:
Slowly tilt the carburetor in the opposite
direction, then take the measurement
when the needle valve aligns with the float
arm.
If the carburetor is level, the weight of the
float will push in the needle valve, result-
ing in an incorrect measurement.
Measure the distance between the mating
surface of the float chamber and top of the
float using a vernier calipers.
NOTE:
The float arm should be resting on the nee-
dle valve, but not compressing the needle
valve.
If the float height is not within specifica-
tion, inspect the valve seat and needle
valve.
If either is worn, replace them both.
If both are fine, adjust the float height by
bending the float tab b on the float.
Recheck the float height.
EC464600
Float
1. Inspect:
Float 1
Damage → Replace.

4 - 19
ENG

CARBURETOR
19. Install:

Carburetor breather hose
1

Refer to “CABLE ROUTING DIA-
GRAM” section in the CHAPTER 2.
NOTE:

Install the breather hose to the carburetor so
that the hose does not bend near where it is
installed.
Å
WR426F
ı
WR400F
Å
1
1
ı
11

Accelerator pump timing adjustment
* Except for USA
Adjustment steps:
NOTE:

In order for the throttle valve height
a
to
achieve the specified value, tuck under the
throttle valve plate
1
the rod
2
etc. with the
same outer diameter as the specified value.
Throttle valve height:
WR426F: 3.10 mm (0.122 in)
*2.25 mm (0.089 in)
WR400F: 6.60 mm (0.260 in)

Fully turn in the accelerator pump adjust-
ing screw
3
.

Check that the link lever
4
has free play
b
by pushing lightly on it.

Gradually turn out the adjusting screw
while moving the link lever until it has no
more free play.

5 - 24
CHASFRONT BRAKE AND REAR BRAKE
4. Install:
Pin 1
Plain washer 2
Cotter pin 3
NOTE:
After installing, check the brake pedal height.
Refer to “REAR BRAKE ADJUSTMENT” sec-
tion in the CHAPTER 3.
New
Front brake hose
1. Install:
Brake hose 1
To brake hose holder 2.
NOTE:
Before tightening the bolt (brake hose holder),
pass the brake hose in front of the axle boss
a, then fit it into the hose groove b so that the
brake hose does not contact the nut (wheel
axle).
2. Install:
Hose cover 1
Plain washer 2
Bolt [hose cover (M8)] 3
Bolt [hose cover (M6)] 4
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..16 Nm (1.6 m · kg, 11 ft · lb)
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
3. Pass the brake hose through the cable
guide 1, then through the guide a on
the protector 2.