Yamaha TZR50 '03 User manual

SERVICE MANUAL
TZR50
X-POWER
’03
5WX-AE1
’03

TZR50’03 / X-POWER’03
SERVICE MANUAL
© 2003 by Yamaha Motor España, S.A.
1st Edition, December 2003
All rights reserved
Any reproduction or non-authorised use of this
material
is expressly prohibited without the consent of
Yamaha Motor España, S.A.

WARNING
This manual has been issued by Yamaha Motor España, S.A., mainly for its use by Yamaha
/MBK dealers and their qualified mechanics. It is not possible to include the full training of
a mechanic in a manual, for which reason we take it for granted that the persons who use
this manual to carry out maintenance and repair work on Yamaha /MBK motorcycles basi-
cally understand mechanical concepts and procedures inherent to motorcycle repair tech-
nology. Without such knowledge, any attempts to repair or service this model may make it
inappropriate for use and/or dangerous.
Yamaha Motor España, S.A. makes a constant effort to improve all the models that it manu-
factures. Any significant modifications and changes which are brought into the specifica-
tions or procedures will be made known to all Authorised Yamaha/MBK dealers and will
appear, where applicable, in future editions of this manual.
TECHNICAL PUBLICATIONS
AFTER-SALES SERVICE
YAMAHA MOTOR ESPAÑA, S.A
HOW TO USE THIS MANUAL
INFORMATION OF PARTICULAR IMPORTANCE
This material is distinguished by the following annotations:
sA danger symbol means: DANGER! TAKE CARE! YOUR SAFETY
IS AT RISK!
ssWARNING Failure to comply with a WARNING may lead to serious injuries
or death for the rider, a bystander or the person inspecting or
repairing the motorcycle.
CAUTION CAUTION indicates the special precautions which have to be
taken to prevent damage to the motorcycle.
NOTE: A NOTE provides key information for making procedures easier
or clearer.

MANUAL FORMAT
All the procedures included in this manual are arranged in sequential format, divided into
stages. The information presented has been grouped together in order to give the mecha-
nic a reference that is easy to read and convenient to handle, containing exhaustive expla-
nations of all the operations for dismantling, repair, assembly and inspection.
In this reviewed format, the condition of each faulty component is followed by an arrow,
which will in turn be followed by the operation required; for example:
• Bearing
• Pitting / Deterioration  Replace
EXPLODED VIEWS
Each chapter includes exploded views, before each dismantling section, to facilitate iden-
tification of the right procedures for dismantling and assembly.

SYMBOLS ILLUSTRATED
(See the ilustration)
Symbols to are designed as thumb tabs,
in order to show the number of the chapter
and index
General information
Specifications
Regular inspection and adjustments
General engine servicing
Carburation
Chassis
Electrical system
Troubleshooting - location and repair of
faults
Symbols to 
15 are used to identify the spe-
cifications appearing in the text
Filling liquid
10 Lubricant

11 Special tool

12 Tightening

13 Limit of wear or clearance

14 Engine speed

15 Ω, V, A
Symbols 
16 to 23 of the detailed diagrams
indicate the grade of lubricant and the loca-
tion of the lubrication point.
16 Apply engine oil

17 Apply gearbox oil

18 Apply molybdenum bisulphide oil

19 Apply grease for wheel bearings

20 Apply lightweight lithium soap-based
grease

21 Apply molybdenum bisulphide grease

22 Apply locking agent (LOCTITE®)

23 Use a new one
INSP/
ADJ
CHAS
TRBL
SPEC
ENG
CARB
GEN
INFO
NEW





11
13
15
16
19
22




10
12
14
23
18
21
17
20
ELEC

SPEC 2
SPECIFICATIONS
INSP
ADJ 3
REGULAR INSPECTIONS
AND ADJUSTMENTS
ENG 4
DISMANTLING THE ENGINE
COOL 5
COOLING SYSTEM
CARB 6
CARBURATION
CHAS 7
CHASSIS
INDEX
ELEC 8
ELECTRICAL SYSTEM
GENERAL INFORMATION GEN/
INFO 1

GEN/
INFO 1

GEN/
INFO
CHAPTER 1
GENERAL INFORMATION
IDENTIFICATION OF THE MOTORCYCLE …………………………………1-1
FRAME SERIAL NUMBER ……………………………………………………1-1
ENGINE SERIAL NUMBER……………………………………………………1-1
IMPORTANT INFORMATION …………………………………………………1-2
PREPARATION FOR REMOVAL AND DISMANTLING ……………………1-2
SPARES …………………………………………………………………………1-3
GASKETS, OIL SEALS AND O RINGS………………………………………1-3
WASHERS, LOCKING PLATES AND SPLIT PINS …………………………1-3
BEARINGS AND OIL SEALS …………………………………………………1-3
CIRCLIPS ………………………………………………………………………1-4
SPECIAL TOOLS …………………………………………………………………1-4
FOR TUNING …………………………………………………………………1-4
FOR ENGINE SERVICE ………………………………………………………1-4
FOR CHASSIS SERVICE ……………………………………………………1-7
FOR ELECTRICAL COMPONENTS …………………………………………1-8

GEN/
INFO
IDENTIFICATION OF THE MOTORCYCLE
1-1
GENERAL INFORMATION
IDENTIFICATION OF THE
MOTORCYCLE
FRAME SERIAL NUMBER
The chassis serial number is printed on the
right-hand side of the steering head.
ENGINE SERIAL NUMBER
The engine serial number is printed on the
left-hand side of the engine.
NOTE:
The first three figures of these numbers are for
identifying the model: the others are the
machine manufacturing number.
NOTE:
Design and characteristics subject to modifi-
cation at no prior notice.



GEN/
INFO
IMPORTANT INFORMATION
1-2
IMPORTANT INFORMATION
PREPARATION FOR REMOVAL
AND DISMANTLING
1. Before starting removal and dismantling,
remove any dirt, mud, dust and foreign
bodies.
2. Use appropriate tools and cleaning equip-
ment
See “SPECIAL TOOLS”
3. When dismantling the motorcycle, keep any
matching parts together. This refers to
gears, cylinders and pistons and other
items which work together and undergo the
same normal wear. Matching parts must be
assembled or replaced together.
4. As you dismantle the motorcycle, clean all
the parts and place them in trays, in the
same order in which these are dismantled.
This will cut down the time required for
assembly and will make it easier to install
them all together.
5. Keep any fire well away. CAREFUL ! NO
SMOKING !

GEN/
INFO
IMPORTANT INFORMATION
1-3
SPARES
1. Use only original Yamaha/MBK spares for
all changes. Use the oils and /or greases
recommended by Yamaha/MBK for
assembly and adjustments. Other makes
may have the same function and appearan-
ce but nevertheless be of lower quality.
GASKETS, OIL SEALS AND O RINGS
1. When an engine is dismantled, all the gas-
kets, oil seals and O rings must be repla-
ced. All the surfaces of all the gaskets and
the lips of oil seals and O rings must also be
cleaned.
2. When assembling, properly lubricate all
bearings and matching parts. Apply grease
to the lips of oil seals.
WASHERS AND LOCKING TABS AND SPLIT
PINS
1. All washers/locking tabs (1) and split pins
have to be replaced and when locking tabs
are removed and replaced they must be fol-
ded over the sides of the bolts or nuts, after
these have been properly tightened.
BEARINGS AND OIL SEALS
1. Install the bearings and oil seals with the
makes or manufacturer numbers facing
outwards. (This means that the printed let-
ters should be visible). When installing oil
seals, apply a thin layer of light lithium gre-
ase to the lips. Put plenty of oil on bearings
when installing these.
Oil seal
CAUTION
Do not use compressed air to dry bearings.
This method damages the surface of these
items.
Bearing

GEN/
INFO
SPECIAL TOOLS
1-4
CIRCLIPS
1. All circlips must be carefully inspected befo-
re installing these again.
Always change the ones on the piston rods
when these are worn. Change any circlip
that has become deformed. When installing
a circlip make sure that the sharp edge 
is facing opposite the direction of the thrust
that this receives. See the section dra-
wing.
Axis
SPECIAL TOOLS
For full and accurate tuning and installing the
appropriate special tools must be used. This
will prevent any damage that could arise from
using inappropriate tools or improvised techni-
ques.
FOR TUNING
1. Comparator set
Ref. 90890-01252
This tool is used for installing the comparator
and tune the motor.
2. Digital tachometer for the engine
Ref. 90890-03113
This tool is required for determining the engine
speed in rpm.
FOR ENGINE SERVICE
1. Universal clutch holder
Ref. 90890-04086
This tool is used for immobilising the clutch
when this is loosened or when the boss loc-
king nut is tightened.

GEN/
INFO
SPECIAL TOOLS
1-5
2. Flywheel (rotor) holding tool
Ref. 90890-01235
This tool is used when the securing screw for
the magnetic flywheel magneto has to be tigh-
tened or loosened.
3. Magnetic flywheel extractor
Ref. 90890-11031
This tool is used for dismantling the magnetic
flywheel.
4. Pin extractor
Ref. 90890-01304
This tool is used for removing the piston pin.
5. Cooling system checker
Ref. 90890-01325
This tool is required for checking the cooling
system.
6. Adapter
Ref. 90890-01352
This system is used for checking the cooling
system.

GEN/
INFO
SPECIAL TOOLS
1-6
7. Crankcase remover tool
Ref. 90890-11030
This tool is used for dismantling the crankshaft
or removing the crankcase.
8. Tools for installing the crankshaft.
Ref. 90890-01284
These tools are used for installing the cranks-
haft.
9. Crankcase installer
(Magnetic flywheel side)
Ref. 90890-11032
10. Seal installer
(Selector axle)
Ref. 90890-11033
11. Seal installer
(Water pump)
Ref. 90890-11034

GEN/
INFO
SPECIAL TOOLS
1-7
12. Seal installer
(Clutch lever)
Ref. 90890-11035
13. Seal installer
(Clutch side of crankshaft)
Ref. 90890-11036)
FOR CHASSIS SERVICE
1. “T” tool –––––––––––––––––––––––––––––
Ref. 90890-01326–––––––––––––––––––––
Front fork cylinder holder––––––––––––––
Ref. 90890-01294
This tool is used to loosen and tighten the
fixing bolts for the cylinders of the front fork.
2. Front fork seal fitter (weight) –––––––––––
Ref. 90890-01367–––––––––––––––––––––
Adapter –––––––––––––––––––––––––––––
Ref. 90890-01400
These tools are used for installing the seals on
the front fork.
3. Wrench for circular nuts
Ref. 90890-01403
This tool is used for loosening and tightening
the circular steering nut.

GEN/
INFO
SPECIAL TOOLS
1-8
FOR ELECTRICAL COMPONENTS
1. Pocket tester
Ref. 90890-03112
This tester is an invaluable help for checking
the electrical system.
2. Stroboscopic lamp
Ref. 90891-03141
This tool is required for checking the ignition
advance.
OTHER TOOLS
1. Micrometer
Ref. 90896 - 03008
2. Feeler gauge
Ref. 90890-03079

SPEC 2

SPEC
CHAPTER 2
GENERAL SPECIFICATIONS
SPECIFICATIONS ………………………………………………………………2-1
GENERAL SPECIFICATIONS …………………………………………………2-1
MAINTENANCE SPECIFICATIONS ……………………………………………2-4
ENGINE …………………………………………………………………………2-4
CHASSIS ………………………………………………………………………2-7
TIGHTENING TORQUES ……………………………………………………2-9
ELECTRICAL SYSTEM ………………………………………………………2-11
GENERAL SPECIFICATIONS OF TIGHTENING TORQUES/
DEFINITION OF THE UNITS …………………………………………………2-13
LUBRICATION POINTS AND TYPE OF LUBRICANT ……………………2-14
ENGINE ………………………………………………………………………2-14
CHASSIS ………………………………………………………………………2-15
CABLE ROUTING ………………………………………………………………2-16

SPEC
GENERAL SPECIFICATIONS
2-1
Model TZR50 / X-POWER
Model code number 5WX
Frame serial number
Yamaha UTLRA031000000001
MBK UTLRA032000000001
Dimensions:
Total length 2007 mm
Total width 675 mm
Total height 1065 mm
Height of the seat 815 mm
Distance between axles 1330 mm
Minimum ground clearance 144 mm
Basic weight:
With oil and full fuel tank 124.2 kg.
Minimum turning radius 2900 mm
Engine:
Type of engine 2 stroke, petrol, liquid cooled
Admission system Reed valve
Cylinder arrangement Single cylinder, slanting forwards
Cylinder capacity 49.7 cm3
Bore x stroke 40.3 x 39 mm
Compression ratio 6.85:1
Starting system Electric
Lubrication system Independent lubrication
Motor oil
Type Yamaha 2 stroke oil or oil for air-cooled 2 stro-
ke engines
Capacity 1.35 L
Transmission oil:
Type Engine oil SAE 10W30 SE type
Capacity:
Regular oil change 0.75 L
Total amount 0.82 L
Capacity of coolant:
Including all routes 0.7 L
Air filter:
Type Damp element
SPECIFICATIONS
GENERAL SPECIFICATIONS