2006 YAMAHA TTR50 engine

CHAPTER 4ENGINE
FRONT FENDER, SEAT ASSEMBLY
AND FUEL TANK .......................................4-1
MUFFLER ...................................................4-3
CARBURETOR ...........................................4-4
CYLINDER HEAD .....................................4-10
CAMSHAFT AND ROCKER ARMS .........4-15
VALVES AND VALVE SPRINGS .............4-18
CYLINDER AND PISTON .........................4-23
CLUTCH ....................................................4-29
SHIFT SHAFT ...........................................4-37
OIL PUMP .................................................4-39
AC MAGNETO AND
STARTER CLUTCH ..................................4-42
ENGINE REMOVAL ..................................4-47
CRANKCASE AND CRANKSHAFT .........4-51
SHIFT FORK, SHIFT CAM AND
TRANSMISSION .......................................4-54
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL ........5-1
HANDLEBAR ............................................5-10
STEERING AND
FRONT SUSPENSION .............................5-13
SWINGARM ..............................................5-17
CHAPTER 6
ELECTRICAL
ELECTRICAL COMPONENTS AND
WIRING DIAGRAM .....................................6-1
IGNITION SYSTEM .....................................6-2
ELECTRIC STARTING SYSTEM ...............6-6
CHARGING SYSTEM ...............................6-14
CARBURETOR HEATING SYSTEM ........6-16
MAINTENANCE RECORD .......................6-20

1 - 1
GEN
INFO
DESCRIPTION
EC100000
GENERAL INFORMATION
EC110000
DESCRIPTION
1 Engine stop switch
2 Starter lever (choke)
3 Main switch
4 Front brake lever
5 Throttle grip
6 Start switch
7 Fuel tank cap
8 Fuel tank
9 Rear brake pedal
0 Fuel cock
A Air cleaner
B Drive chain
C Shift pedal
D Front fork
E Reflector (For Canada)
NOTE:

The machine you have purchased may differ
slightly from those shown in the following.
 Designs and specifications are subject to
change without notice.
1
4
7
5
2 6
3
\b
8
EE
0\f
DC B
1

1 - 2
GEN
INFO
MACHINE IDENTIFICATION
EC120001
MACHINE IDENTIFICATION
There are two significant reasons for knowing
the serial number of your machine:
1. When ordering parts, you can give the
number to your Yamaha dealer for positive
identification of the model you own.
2. If your machine is stolen, the authorities will need the number to search for and identify
your machine.
KEY IDENTIFICATION NUMBER
The key identification number 1 is stamped
on the key as shown in the following illustra-
tion. This number can be used for ordering a
new key.
EC121001
VEHICLE IDENTIFICATION NUMBER
The vehicle identification number 1 is
stamped on the right of the steering head pipe.
1
ENGINE SERIAL NUMBER
The engine serial number 1 is stamped into
the elevated part of the left-side of the engine.
1
EC124000
MODEL LABEL
The model label 1 is affixed to the frame
under the rider ’s seat. This information will be
needed to order spare parts.
1

1 - 4
GEN
INFO
IMPORTANT INFORMATION
EC132000
ALL REPLACEMENT PARTS
1. We recommend to use Yamaha genuine
parts for all replacements. Use oil and/or
grease recommended by Yamaha for
assembly and adjustment.
EC133000
GASKETS, OIL SEALS AND O-RINGS
1. All gaskets, oil seals, and O-rings shouldbe replaced when an engine is overhauled.
All gasket surfaces, oil seal lips, and O-
rings must be cleaned.
2. Properly oil all mating parts and bearings
during reassembly. Apply grease to the oil
seal lips.
EC134000
LOCK WASHERS/PLATES AND COTTER
PINS
1. All lock washers/plates 1 and cotter pins
must be replaced when they are removed.
Lock tab(s) should be bent along the bolt or
nut flat(s) after the bolt or nut has been
properly tightened.
EC135001
BEARINGS AND OIL SEALS
1. Install the bearing(s) 1 and oil seal(s) 2
with their manufacturer ’s marks or numbers
facing outward. (In other words, the
stamped letters must be on the side
exposed to view.) When installing oil
seal(s), apply a light coating of light-weight
lithium base grease to the seal lip(s). Oil
the bearings liberally when installing.
CAUTION:
Do not use compressed air to spin the
bearings dry. This causes damage to the
bearing surfaces.

1 - 8
GEN
INFO
CONTROL FUNCTIONS
EC150000
CONTROL FUNCTIONS
MAIN SWITCH
Functions of the respective switch positions
are as follows:
ON: The engine can be started only at this
position.
OFF: All electrical circuits are switched off. The key can be removed in this position.
ENGINE STOP SWITCH
Make sure that the engine stop switch 1 is
positioned to “”. The engine stop switch has
been equipped to ensure safety in an emer-
gency such when the machine is up set or
trouble takes place in the throttle system. The
engine will not start or run when the engine
stop switch is turned to “”.
START SWITCH
The start switch 1 is located on the right han-
dlebar. Push this switch to crank the engine
with the starter.
1
SHIFT PEDAL
The gear ratios of the constant-mesh 3 speed
transmission are ideally spaced. The gears
can be shifted by using the shift pedal 1 on
the left side of the engine.
WARNING
When starting out on the machine, shift the
transmission into 1st after pulling in the
front brake lever and closing the throttle
grip.
3
2
1
N
1

1 - 9
GEN
INFO
CONTROL FUNCTIONS
EC155001
THROTTLE GRIP
The throttle grip 1 is located on the right han-
dlebar; it accelerates or decelerates the
engine. For acceleration, turn the grip toward
you; for deceleration, turn it away from you.
1
EC156000
FRONT BRAKE LEVER
The front brake lever 1 is located on the right
handlebar. Pull it toward the handlebar to acti-
vate the front brake.
1
EC157000
REAR BRAKE PEDAL
The rear brake pedal 1 is located on the right
side of the machine. Press down on the brake
pedal to activate the rear brake.
1
FUEL COCK
The fuel cock supplies fuel from the tank to
carburetor while filtering the fuel. The fuel cock
has the three positions:
OFF: With the lever in this position, fuel will not flow. Always return the lever to this posi-
tion when the engine is not running.
ON: With the lever in this position, fuel flows to the carburetor. Normal riding is done
with the lever in this position.
RES: This indicates reserve. If you run out of fuel while riding, move the lever to this
position. FILL THE TANK AT THE FIRST
OPPORTUNITY. BE SURE TO SET
THE LEVER TO “ON ” AFTER REFUEL-
ING.

1 - 10
GEN
INFO
CONTROL FUNCTIONS
STARTER LEVER (CHOKE)
When cold, the engine requires a richer air/fuel
mixture for starting. A separate starter circuit,
which is controlled by the starter lever 1, sup-
plies this mixture.
Pull the lever out to open the circuit (for start-
ing) and push the lever in to close the circuit.
1
FUEL TANK CAP
Remove the fuel tank cap 1 by turning
counter-clockwise.
WARNING
Do not overfill the fuel tank. Avoid spilling
fuel on the hot engine.
1
SIDESTAND
This sidestand 1 is used to support only the
machine when standing or transporting it.
WARNING
 Never apply additional force to the side-
stand.
Hold up the sidestand before starting out.1

1 - 11
GEN
INFO
FUEL
Use regular gasoline. Always use fresh, name
brand gasoline.
WARNING
Do not overfill the fuel tank. Avoid spilling
fuel on the hot engine. Do not fill the fuel
tank above the bottom of the filler tube 1
as shown in the illustration or it may over-
flow when the fuel heats up later and
expands.
a Fuel level
CAUTION:
Use only unleaded gasoline. The use of
leaded gasoline will cause severe damage
to the engine internal parts such as valves,
piston rings, and exhaust system, etc.
Recommended fuel: For USA, AUS and NZ: Unleaded gasoline only
For CDN, EUROPE and ZA: Regular unleaded gasoline
only
Fuel tank capacity: Total: 3.1 L (0.68 Imp gal, 0.82 US gal)
Reserve: 0.4 L (0.09 lmp gal, 0.11 US gal)
FUEL