2006 YAMAHA TTR50 length

3 - 16
INSPADJ
EC369002
DRIVE CHAIN INSPECTION
1. Remove:
Master link clip
 Joint 1
 Drive chain 2
2. Clean:
Drive chain
Place it in kerosene, and brush off as
much dirt as possible. Then remove the
chain from the kerosene and dry the
chain.
3. Measure:
Drive chain length (15 links) a
Out of specification → Replace.
Drive chain length (15 links):
: 194.3 mm (7.65 in)
4. Check:
Drive chain stiffness a
Clean and oil the chain and hold as illus-
trated.
Stiff → Replace drive chain.
5. Install:
Drive chain 1
 Joint 2
 Master link clip 3
CAUTION:
Be sure to install the master link clip to the
direction as shown.
a Turning direction
New
DRIVE CHAIN INSPECTION

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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 bolt:
YU-01083-1/90890-01083
Weight: YU-01083-3/90890-01084
INSPECTION
Camshaft
1. Measure:
Cam lobes length a and b
Out of specification → Replace.
Cam lobes length limit:
Intake:
a 25.328 mm (0.9972 in)
b 20.934 mm (0.8242 in)
Exhaust:
a 25.186 mm (0.9916 in)
b 20.947 mm (0.8247 in)
ASSEMBLY AND INSTALLATION
1. Apply:
Molybdenum disulfide oil
(onto the camshaft cam lobe)
 Engine oil
(onto the camshaft bearing)
2. Install: Camshaft 1

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ENGVALVES AND VALVE SPRINGS
Valve spring
1. Measure:Valve spring free length a
Out of specification → Replace.
2. Measure: Spring tilt a
Out of specification → Replace.
Free length (valve spring):
Intake: 32.45 mm (1.28 in)
: 30.83 mm (1.21 in)
Exhaust: 32.45 mm (1.28 in)
: 30.83 mm (1.21 in)
Spring tilt limit:Intake: 2.5 °/1.4 mm (0.06 in)
Exhaust: 2.5 °/1.4 mm (0.06 in)
Valve seat
1. Measure:
Valve seat width a
Out of specification → Reface the valve
seat.
Valve seat width: Intake: 0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)
: 1.6 mm (0.0630 in)
Exhaust: 0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)
: 1.6 mm (0.0630 in)
Measurement steps:
 Apply Mechanic ’s blueing dye (Dykem) b
to the valve face.
 Install the valve into the cylinder head.
 Press the valve through the valve guide
and onto the valve seat to make a clear
pattern.
 Measure the valve seat width. Where the
valve seat and valve face made contact,
blueing will have been removed.
 If the valve seat is too wide, too narrow, or
the seat is not centered, the valve seat
must be refaced.

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–+ELEC
5. Measure:
Brush length a
Out of specification → Replace.
Brush length wear limit:
3.5 mm (0.14 in)
6. Measure:
Brush spring force
Fatigue/out of specification → Replace as
a set.
Brush spring force: 3.92 ~ 5.88 N
(400 ~ 600 g, 14.1 ~ 21.2 oz)
ASSEMBLY
1. Install:
Brush holder
2. Install:
Armature coil 1
3. Install:
Ring 1
 Starter motor yoke 2
 Front bracket 3
NOTE:
Apply molybdenum disulfide grease lightly
on to the bearings of the starter motor.
 Align the match mark on the armature
assembly with the match mark on the front
bracket.
ELECTRIC STARTING SYSTEM