engine YAMAHA TTR50 2006 Workshop Manual

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

4 - 47
ENGENGINE REMOVAL
ENGINE REMOVAL
(4)
NewNew
LS
T R..30 Nm (3.0 m • kg, 22 ft • Ib)
T R..30 Nm (3.0 m •
kg, 22 ft • Ib)
T R..30 Nm (3.0 m •
kg, 22 ft • Ib)
T R..30 Nm (3.0 m •
kg, 22 ft • Ib)
T R..48 Nm (4.8 m •
kg, 35 ft • Ib)
T R..7 Nm (0.7 m •
kg, 5.1 ft • Ib)
T R..10 Nm (1.0 m • kg, 7.2 ft • Ib)
(3)
10
4
1 6
2
9
3
11
7
5 8
Extent of removal:
1 Engine removal
Extent of removal Order Part name Q ’ty Remarks
ENGINE REMOVAL
Preparation for removal Hold the machine by placing the suitable stand under the frame.
Seat assembly, fuel tank air filter
case cover and air filter case Refer to
“FRONT FENDER, SEAT
ASSEMBLY AND FUEL TANK ” section.
Carburetor Refer to “CARBURETOR ” section.
Muffler Refer to “MUFFLER ” section.
Spark plug cap
Disconnect the AC magneto cou-
plers.
Disconnect the neutral switch
lead.
Starter motor Refer to “ELECTRIC STARTING SYS-
TEM ” section in the CHAPTER 6.

4 - 48
ENGENGINE REMOVAL
(4)
NewNew
LS
T R..30 Nm (3.0 m • kg, 22 ft • Ib)
T R..30 Nm (3.0 m •
kg, 22 ft • Ib)
T R..30 Nm (3.0 m •
kg, 22 ft • Ib)
T R..30 Nm (3.0 m •
kg, 22 ft • Ib)
T R..48 Nm (4.8 m •
kg, 35 ft • Ib)
T R..7 Nm (0.7 m •
kg, 5.1 ft • Ib)
T R..10 Nm (1.0 m • kg, 7.2 ft • Ib)
(3)
10
4
1 6
2
9
3
11
7
5 8
Extent of removal Order Part name Q
’ty Remarks
Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT ”
section in the CHAPTER 3.
1 Drive sprocket cover 1
2 Drive sprocket 1
3 Shift pedal 1
4 Brake pedal 1
5 Footrest 1
6 Crankcase breather hose 1
7 Engine mounting bolt (front upper side) 1
8 Engine bracket 1
1

4 - 49
ENGENGINE REMOVAL
(4)
NewNew
LS
T R..30 Nm (3.0 m • kg, 22 ft • Ib)
T R..30 Nm (3.0 m •
kg, 22 ft • Ib)
T R..30 Nm (3.0 m •
kg, 22 ft • Ib)
T R..30 Nm (3.0 m •
kg, 22 ft • Ib)
T R..48 Nm (4.8 m •
kg, 35 ft • Ib)
T R..7 Nm (0.7 m •
kg, 5.1 ft • Ib)
T R..10 Nm (1.0 m • kg, 7.2 ft • Ib)
(3)
10
4
1 6
2
9
3
11
7
5 8
Extent of removal Order Part name Q
’ty Remarks
9 Engine mounting bolt (rear upper side) 1
10 Engine mounting bolt (rear lower side) 1
11 Engine 1 Refer to “REMOVAL POINTS ”.
1

4 - 50
ENG
REMOVAL POINTS
Engine removal
1. Remove:Engine 1
From left side.
NOTE:
Make sure that the couplers, hoses and cables
are disconnected.1
ASSEMBLY AND INSTALLATION
Engine installation
1. Install: Engine 1
Install the engine from left side.
 Engine mounting bolt (rear lower side) 2
 Engine mounting bolt (rear upper side) 3
 Engine bracket 4
 Bolt (engine bracket) 5
 Engine mounting bolt (front) 6 5
3
2
4
1
6
T R..48 Nm (4.8 m · kg, 35 ft · lb)
T R..30 Nm (3.0 m · kg, 22 ft · lb)
T R..30 Nm (3.0 m · kg, 22 ft · lb)
T R..30 Nm (3.0 m · kg, 22 ft · lb)
ENGINE REMOVAL

4 - 51
ENGCRANKCASE AND CRANKSHAFT
CRANKCASE AND CRANKSHAFT
E
T R..10 Nm (1.0 m • kg, 7.2 ft • Ib)
T R..10 Nm (1.0 m •
kg, 7.2 ft • Ib)
LT
4
4 3
4
4
5 6
7
9
8
8
12
5 6
4
Extent of removal Order Part name Q ’ty Remarks
CRANKCASE SEPARATION
AND CRANKSHAFT REMOVAL
Preparation for removal Seat assembly and fuel tank
Exhaust pipe
Air filter case and bottom cover Refer to “FRONT FENDER, SEAT
ASSEMBLY AND FUEL TANK ” section.
Carburetor Refer to “CARBURETOR ” section.
Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT ”
section in the CHAPTER 3.
Drive sprocket Refer to “ENGINE REMOVAL ”.
Cylinder head Refer to “CYLINDER HEAD ” section.
Cylinder and piston Refer to “CYLINDER AND PISTON ” sec-
tion.
Primary driven gear Refer to “CLUTCH ” section.

4 - 54
ENGSHIFT FORK, SHIFT CAM AND TRANSMISSION
SHIFT FORK, SHIFT CAM AND TRANSMISSION
0.8~1.3mm
(0.03~0.05 in)
New
New
New
New
M
M
12 13 14
15 16
17 18
19
7
8
9
10
11
4 3
1
2
M
E
5 6
Extent of removal:
1 Shift fork, shift cam, main axle and drive axle removal
2 Main axle disassembly
3 Drive axle disassembly
Extent of removal Order Part name Q ’ty Remarks
SHIFT FORK, SHIFT CAM AND
TRANSMISSION REMOVAL
Preparation for removal Engine assembly Separate the crankcase. Refer to “CRANKCASE AND CRANK-
SHAFT ”section.
1 Guide bar 1
2Shift cam 1
Refer to “REMOVAL POINTS ”.
3 Shift fork 1
“L ” 1
4 Shift fork 2 “R ” 1
5 Main axle assembly 1
6 Drive axle assembly 1
7 2nd pinion gear 1
8 Circlip 1
9 Washer 1
2
1

4 - 57
ENGSHIFT FORK, SHIFT CAM AND TRANSMISSION
2. Install:Main axle assembly 1
 Drive axle assembly 2
 Shift fork 2 “R ” 3
 Shift fork 1 “L ” 4
 Shift cam 5
 Guide bar 6
NOTE:
The embossed marks on the shift forks
should face towards the right side of the
engine and be in the following sequence:
“R ”, “L ”.
 Mesh the shift fork 2 “R ” with the 3rd wheel
gear on the drive axle.
 Mesh the shift fork 1 “L ” with the 2nd pinion
gear on the main axle.
3. Check: Shifter operation
 Transmission operation
Unsmooth operation → Repair.
3
4
5 1
6
2

5 - 1
CHAS
EC500000
CHASSIS
FRONT WHEEL AND REAR WHEEL
FRONT WHEEL AND FRONT BRAKE
Extent of removal:1 Front wheel removal
2 Wheel bearing removal
3 Brake shoe plate assembly removal and disassembly
Extent of removal Order Part name Q ’ty Remarks
FRONT WHEEL REMOVAL
WARNING
Support the machine securely so
there is no danger of it falling over.
Preparation for removal Hold the machine by placing the
suitable stand under the engine.
1 Front brake adjuster 1
2Pin 1
3Spring 1
4 Locknut 1
5 Brake cable 1 Disconnect at the lever side.
6 Front fork guard (left) 1
7 Front fork guard (right) 1
8 Wheel axle nut 1
9 Front wheel axle 1
21
FRONT WHEEL AND REAR WHEEL

5 - 3
CHASFRONT WHEEL AND REAR WHEEL
REAR WHEEL AND REAR BRAKE
Extent of removal:1 Rear wheel removal
2 Wheel bearing removal
3 Brake shoe plate assembly removal and disassembly
Extent of removal Order Part name Q ’ty Remarks
REAR WHEEL REMOVAL
WARNING
Support the machine securely so
there is no danger of it falling over.
Preparation for removal Hold the machine by placing the
suitable stand under the engine.
1 Rear brake adjuster 1
2Pin 1
3Spring 1
4 Drive chain locknut 2
5 Wheel axle nut 1
6 Rear wheel axle 1
7 Drive chain puller 2
8 Rear wheel 1
9 Collar (left) 1
10 Brake shoe plate assembly 1
2
1
3