2004 YAMAHA TTR90 weight

4 - 5
ENG

CARBURETOR
EC464401
Jet needle
1. Inspect:

Jet needle
1
Bends/wear → Replace.
Clip groove
Free play exists/wear → Replace.
Clip position
Float height
1. Measure:
Float height a
Out of specification → Adjust.
Standard clip position:
No.2 Groove
Float height:
15.5 ~ 16.5 mm (0.61 ~ 0.65 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 1 on the float.
Recheck the float height.

4 - 14
ENGCAMSHAFT AND ROCKER ARMS
REMOVAL POINTS
Rocker arm shaft
1. Remove:
Rocker arm shafts
NOTE:
Use a slide hammer bolt 1 and weight 2 to
slide out the rocker arm shafts.
Slide hammer set:
YU-1083-A
Slide hammer bolt:
90890-01085
Weight:
90890-01084
INSPECTION
Camshaft
1. Measure:
Cam lobes length a and b
Out of specification → Replace.
Cam lobes length limit:
Intake:
a 25.398 mm (0.9999 in)
b 21.004 mm (0.8269 in)
Exhaust:
a 25.256 mm (0.9943 in)
b 21.017 mm (0.8274 in)
ASSEMBLY AND INSTALLATION
1. Apply:
Molybdenum disulfide oil
(onto the camshaft cam lobe)
Engine oil
(onto the camshaft bearing)
2. Install:
Camshaft 1

5 - 8
CHASFRONT FORK
REMOVAL POINTS
Inner tube
1. Remove:
Bolt (damper rod)
NOTE:
While holding the damper rod with the damper
rod holder 1 and T-handle 2, loosen the bolt
(damper rod).
Damper rod holder:
YM-1300/90890-01294
T-handle:
YM-1326/90890-01326
EC555000
ASSEMBLY AND INSTALLATION
Front fork assembly
1. Install:
Oil seal 1
NOTE:
Press the oil seal into the outer tube with fork
seal driver weight 2 and fork seal driver
attachment 3.
2. Fill:
Fork oil
3. After filling up, slowly pump the fork up
and down to distribute the fork oil.
Fork seal driver weight:
YM-33963/90890-01184
Fork seal driver attachment:
90890-01186
Oil quantity:
64 cm3 (2.26 Imp oz, 2.16 US oz)
Recommended oil:
Fork oil 15W or equivalent