2006 YAMAHA TTR50 engine

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INSPADJ
ENGINE/THROTTLE CABLE ADJUSTMENT
EC350000
ENGINE
THROTTLE CABLE ADJUSTMENT
1. Check:
Throttle grip free play a
Out of specification → Adjust.
Throttle grip free play
a:
3 ~ 5 mm (0.12 ~ 0.20 in)
2. Adjust:
Throttle grip free play
Throttle grip free play adjustment steps:
Carburetor side
NOTE:
Before adjusting the throttle cable free play,
the engine idle speed should be adjusted.
 Remove the seat assembly and air scoop
(right).
Refer to “FRONT FENDER, SEAT
ASSEMBLY AND FUEL TANK ” section in
the CHAPTER 4.
 Pull back the adjuster cover.
 Loosen the locknut 1 on throttle cable.
 Turn the adjuster 2 in or out until the
specified free play is obtained.
Turning in b → Free play is increased.
Turning out c → Free play is decreased.
 Tighten the locknut.
 Slide the adjuster cover to its original posi-
tion.
 Install the seat assembly and air scoop
(right).
NOTE:
If the specified throttle cable free play can-
not be obtained on the carburetor side of the
cable, use the adjusting nut on the handle-
bar side.
WARNING
After adjusting, turn the handlebar to
right and left and make sure that the
engine idling does not run faster.
c
b
1
2

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INSPADJTHROTTLE CABLE ADJUSTMENT/
SPEED LIMITER ADJUSTMENT
Handlebar side
Loosen the locknut 3 on throttle cable.
 Turn the adjuster 4 in or out until the
specified free play is obtained.
Turning in d → Free play is increased.
Turning out e → Free play is decreased.
 Tighten the locknut.
WARNING
After adjusting, turn the handlebar to
right and left and make sure that the
engine idling does not run faster.
4
d
e
3
SPEED LIMITER ADJUSTMENT
The speed limiter keeps the carburetor throttle
from becoming fully-opened even when the
throttle lever is applied to the maximum posi-
tion. Screwing in the adjuster stops the engine
speed from increasing.
1. Measure:

speed limiter length a
Out of specification → Adjust.
2. Adjust:
 speed limiter length
Speed limiter length:
Less than 25 mm (0.98 in)
Speed limiter adjustment steps:
 Loosen the locknut 1.
 Turn the adjuster 2 in or out until the
specified speed limiter length is obtained.
Turning in a → Speed limiter length is
decreased.
Turning out b → Speed limiter length is
increased.
a
1 2
a
b

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INSPADJ
 Tighten the locknut.
WARNING
Particularly for a beginner rider, the
speed limiter should be screwed in
completely. Screw it out little by little as
their riding technique improves. Never
remove the speed limiter for a begin-
ning rider.
 For proper throttle lever operation do
not turn out the adjuster more than
25.0 mm (0.98 in). Also, always adjust
the throttle lever free play to 3 ~ 5 mm
(0.12 ~ 0.20 in).
AIR FILTER CLEANING
NOTE:
Proper air filter maintenance is the biggest key
to preventing premature engine wear and
damage.
CAUTION:
Never run the engine without the air filter
element in place; this would allow dirt and
dust to enter the engine and cause rapid
wear and possible engine damage.
1. Remove: Seat assembly
 Air scoop (left)
Refer to “FRONT FENDER, SEAT
ASSEMBLY AND FUEL TANK ” section in
the CHAPTER 4.
 Air filter case cover 1
 Air filter element
1
SPEED LIMITER ADJUSTMENT/AIR FILTER CLEANING

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INSPADJ
2. Clean:
Air filter element
Clean it with solvent.
NOTE:
After cleaning, remove the remaining solvent
by squeezing the element.
CAUTION:
 Do not twist the element when squeezing
the element.
 Leaving too much of solvent in the ele-
ment may result in poor starting.
3. Inspect: Air filter element
Damage → Replace.
4. Apply: Foam-air-filter oil or engine oil
To the element.
NOTE:
Squeeze out the excess oil. Element should be
wet but not dripping.
5. Install:
Air filter element
 Air filter case cover
 Air scoop (left)
 Seat assembly
ENGINE OIL LEVEL INSPECTION
1. Start the engine, warm it up for several
minutes, and then turn off the engine and
wait for five minutes.
2. Place the machine on a level place and hold it up on upright position by placing the
suitable stand under the engine.
3. Remove: Oil filler cap 1
1
AIR FILTER CLEANING/
ENGINE OIL LEVEL INSPECTION

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INSPADJ
4. Check:
Oil level
Oil level should be between maximum a
and minimum b marks.
Oil level is low → Add oil to proper level.
NOTE:
Wait a few minutes until the oil settles before
inspecting the oil level.
 When inspecting the oil level, do not screw
the dipstick into the oil tank. Insert the gauge
lightly.
(For USA and CDN)
CAUTION:
 Do not add any chemical additives.
Engine oil also lubricates the clutch and
additives could cause clutch slippage.
 Do not allow foreign material to enter the
crankcase.
(Except for USA and CDN)
CAUTION:
 Do not add any chemical additives or use
oils with a grade of CD a or higher.
 Do not use oils labeled “ENERGY CON-
SERVING II ” b or higher. Engine oil also
lubricates the clutch and additives could
cause clutch slippage.
 Do not allow foreign materials to enter the
crankcase.
Recommended oil:
At –10 °C (14 °F) or higher È:
Yamalube 4 (10W-30) or SAE
10W-30 type SE/SF/SG motor
oil
At 5 °C (41 °F) or higher É:
Yamalube 4 (20W-40) or SAE
20W-40 type SE/SF/SG motor
oil
Recommended oil: Refer to the following chart for
selection of oils which are suited
to the atmospheric temperatures.
Recommended engine oil classifi-
cation:
API STANDARD: API “SE/SF/SG ” or higher grade
(Designed primarily for
motorcycles)
0 10 30 50 70
90110
130
-20 -10 010
20 30 40 50
È
É
˚C
˚
F
a
b
ENGINE OIL LEVEL INSPECTION

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INSPADJENGINE OIL LEVEL INSPECTION/
ENGINE OIL REPLACEMENT
5. Install:
Oil filler cap
6. Start the engine and let it warm up for sev-
eral minutes.
7. Turn off the engine and inspect the oil level once again.
NOTE:
Wait a few minutes until the oil settles before
inspecting the oil level.
ENGINE OIL REPLACEMENT
1. Start the engine and warm it up for severalminutes, and then turn off the engine and
wait for five minutes.
2. Place the machine on a level place and hold it on upright position by placing the
suitable stand under the engine.
3. Place a suitable container under the engine.
4. Remove:
Oil filler cap 1
 Drain bolt (with gasket) 2
Drain the crankcase of its oil.
5. Install: Gasket
 Drain bolt
6. Fill: Crankcase
7. Install: Oil filler cap
8. Inspect: Engine (for oil leaks)
 Oil level
Refer to “ENGINE OIL LEVEL INSPEC-
TION ” section.
Oil quantity:
Periodic oil change: 0.8 L (0.70 Imp qt, 0.85 US qt)
1
2
New
T R..20 Nm (2.0 m · kg, 14 ft · lb)

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INSPADJIDLE SPEED ADJUSTMENT/
VALVE CLEARANCE ADJUSTMENT
IDLE SPEED ADJUSTMENT
1. Start the engine and thoroughly warm it up.
2. Attach:
Tachometer
To spark plug lead.
3. Adjust:
Idle speed
Adjustment steps:
Turn the throttle stop screw 1 until the
engine runs at the lowest possible speed.
To increase idle speed → Turn the throt-
tle stop screw 1 in
a.
To decrease idle speed → Turn the throt-
tle stop screw 1 out
b.
Engine idling speed:
1,600 ~ 1,800 r/min
1
a
b
VALVE CLEARANCE ADJUSTMENT
NOTE:
 The valve clearance should be adjusted
when the engine is cool to the touch.
 The piston must be at Top Dead Center
(T.D.C.) on compression stroke to check or
adjust the valve clearance.
1. Remove: Spark plug cap 1
 Spark plug
 Tappet cover (intake side) 2
 Tappet cover (exhaust side) 3
 Camshaft sprocket cover 4
3
4
1
2
2. Remove:
Timing plug 1
 Crankshaft end cover 2
 O-rings
1
2

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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)