2006 YAMAHA TTR50 engine oil

3 - 13
INSPADJVALVE CLEARANCE ADJUSTMENT/
SPARK ARRESTER CLEANING (For USA)
6. Install:
Spark plug
 Spark plug cap
 Timing plug
 Crankshaft end cover
NOTE:
Apply the engine oil on the O-ring.
T R..13 Nm (1.3 m · kg, 9.4 ft · lb)
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
SPARK ARRESTER CLEANING (For USA)
WARNING
 Be sure the exhaust pipe and muffler are
cool before cleaning the spark arrester.
 Do not start the engine when cleaning the
exhaust system.
1. Remove: Bolts (spark arrester) 1
2. Remove:
Spark arrester 2
Pull the spark arrester out of the muffler.
3. Clean:
Spark arrester
Tap the spark arrester lightly, then use a
wire brush to remove any carbon depos-
its.
4. Install: Spark arrester
Insert the spark arrester into the muffler
and align the bolt holes.
 Bolts (spark arrester)
1
2
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

3 - 17
INSPADJ
6. Lubricate:
Drive chain
Drive chain lubricant:
SAE 10W-30 motor oil or
suitable chain lubricants
DRIVE CHAIN SLACK ADJUSTMENT
1. Elevate the rear wheel by placing the suit-
able stand under the engine.
2. Check: Drive chain slack a
In the center between the drive axle and
rear wheel axle.
Out of specification → Adjust.
NOTE:
Before checking and/or adjusting, rotate the
rear wheel through several revolutions and
check the slack several times to find the tight-
est point. Check and/or adjust chain slack with
rear wheel in this “tight chain ” position.
Drive chain slack:
35 ~ 45 mm (1.38 ~ 1.77 in)
3. Adjust:
Drive chain slack
Drive chain slack adjustment steps:
 Loosen the wheel axle nut 1 and locknuts
2 .
 Adjust chain slack by turning the adjusters
3 .
To tighten → Turn adjuster 3 clockwise a.
To loosen → Turn adjuster 3 counter-
clockwise b and push wheel forward.
 Turn each adjuster exactly the same
amount to maintain correct axle alignment.
(There are marks c on each side of chain
puller alignment.)
1 b
c
a
23
DRIVE CHAIN INSPECTION/
DRIVE CHAIN SLACK ADJUSTMENT

3 - 18
INSPADJDRIVE CHAIN SLACK ADJUSTMENT/
FRONT FORK INSPECTION/REAR SHOCK ABSORBER INSPECTION
NOTE:
Turn the adjuster so that the chain is in line
with the sprocket, as viewed from the rear.
CAUTION:
Too small chain slack will overload the
engine and other vital parts; keep the
slack within the specified limits.
 Tighten the wheel axle nut while pushing
down the drive chain.
T R..
Axle nut:
60 Nm (6.0 m  kg, 43 ft  lb)
 Tighten the locknuts.
T R..
Locknut:
7 Nm (0.7 m  kg, 5.1 ft  lb)
EC36C000
FRONT FORK INSPECTION
1. Inspect:
Front fork smooth action
Operate the front brake and stroke the
front fork.
Unsmooth action → Repair or replace.
EC36K000
REAR SHOCK ABSORBER INSPECTION
1. Inspect:
Swingarm smooth action
Abnormal noise/unsmooth action →
Grease the pivoting points or repair the
pivoting points.
Damage/oil leakage → Replace.

4 - 13
ENGCYLINDER HEAD
4. Remove:Cylinder head
NOTE:
 Loosen the bolts and nuts in their proper
loosening sequence.
 Start by loosening each bolt and nut 1/2 turn
until all are loose.1
2
5
64
3
ASSEMBLY AND INSTALLATION
1. Install:
Cylinder head
2. Tighten: Nuts
 Bolts
NOTE:
 Apply the engine oil on the contact surfaces
of the nuts and copper washers.
 Apply the engine oil on the thread and con-
tact surface of the bolts.
 Follow the numerical order shown in the illus-
tration. Tighten the bolts and nuts in two
stages.
6
5
2
13
4
T R..22 Nm (2.2 m · kg, 16 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
3. Install:
Camshaft sprocket 1
Installation steps:
 Turn the crankshaft counterclockwise until
the “I” mark a on the rotor is aligned with
the stationary pointer b on the crankcase
cover.
 Align the “I” mark c on the camshaft
sprocket with the stationary pointer d on
the cylinder head.
 Fit the timing chain 2 onto camshaft
sprocket and install the camshaft sprocket
on the camshaft.
NOTE:
When installing the camshaft sprocket, keep
the timing chain as tense as possible on the
exhaust side.
b
a
1
2
c
d

4 - 16
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

4 - 27
ENGCYLINDER AND PISTON
Piston pin
1. Inspect:Piston pin
Blue discoloration/grooves →
Replace, then inspect the lubrication sys-
tem.
2. Measure: Piston pin outside diameter
 Piston pin bore inside diameter
ASSEMBLY AND INSTALLATION
Piston
1. Install: Piston rings
(onto the piston)
NOTE:
 Be sure to install the piston rings so that the
manufacturer ’s marks or numbers are
located on the upper side of the rings.
 Lubricate the piston and piston rings liberally
with engine oil.
Measurement steps:

Measure the piston pin outside diameter
a .
If out of specification, replace the piston
pin.
Outside diameter (piston pin): 11.996 ~ 12.000 mm
(0.4723 ~ 0.4724 in)
:11.976 mm (0.4715 in)
 Measure the piston inside diameter b.
If out of specification, replace the piston.
Inside diameter (piston): 12.002 ~ 12.013 mm
(0.4725 ~ 0.4730 in)
: 12.043 mm (0.4741 in)

4 - 28
ENGCYLINDER AND PISTON
2. Position:Top ring
 2nd ring
 Oil ring
Offset the piston ring end gaps as shown.
a Top ring
b Upper oil ring rail
c Oil ring expander
d Lower oil ring rail
e 2nd ring
f 20 mm (0.79 in)
È Intake side
3. Install:
Piston 1
 Piston pin 2
 Piston pin clips 3
NOTE:
Apply engine oil onto the piston pin, piston
ring and piston.
 Be sure that the arrow mark
a on the piston
points to the exhaust side of the engine.
 Before installing the piston pin clip, cover the
crankcase with a clean rag to prevent the
piston pin clip from falling into the crankcase.
4. Lubricate: Piston
 Piston rings
 Cylinder
NOTE:
Apply a liberal coating of engine oil.
Cylinder
1. Install:
Dowel pins
 Gasket
 Cylinder 1
NOTE:
Install the cylinder with one hand while com-
pressing the piston rings with the other hand.
CAUTION:
 Be careful not to damage the timing chain
damper during installation.
 Pass the timing chain through the timing
chain cavity.
e a
ff
d cb120
˚
120 ˚ 120˚
È
New
1
New

4 - 46
ENGAC MAGNETO AND STARTER CLUTCH
3. Install:Spring 1
 Spring cap 2
 Pin 3
4. Install: Shim 1
 Starter wheel gear 2
 Starter idle gear 3
 Shaft 4
NOTE:
Apply the molybdenum disulfide oil on the
starter wheel gear inner circumference.
 Apply the engine oil on the starter idle gear
inner circumference and on the shaft outer
circumference.
1 2
3
12
3
5. Install:
Woodruff key 1
 Rotor 2
NOTE:
Clean the tapered portion of the crankshaft
and the rotor hub.
 When installing the rotor, make sure the
woodruff key is properly seated in the key
way of the crankshaft.
6. Tighten: Rotor nut 1
NOTE:
Tighten the rotor nut 1 while holding the
rotor 2 with a sheave holder 3.
 Do not allow the sheave holder to touch the
projection on the rotor.
7. Install: Crankcase cover (left)
NOTE:
 Pass the starter motor lead 1 and neutral
switch lead 2 into the crankcase cover
groove as shown.
 Fasten the starter motor lead with the clamp 3.
Sheave holder:
YS-01880-A/90890-01701
T R..48 Nm (4.8 m · kg, 35 ft · lb)
3
1
2