Yamaha AEROX YQ50 User manual

SERVICE
MANUAL
YQ50 5BS-AE2
'97

YQ50
SERVICE MANUAL
© 1997 by MBK INDUSTRIE
2st Edition, November 1997
All rights reserved. Any
reprinting or unauthorized use
without the written
permission of MBK INDUSTRIE
is expressly prohibited.

CAUTION:
WARNING
NOTICE
This manual was written by the MBK INDUSTRIE primarily for use by YAMAHA and MBK dealers
and their qualified mechanics. It is not possible to put an entire mechanic’s education into one manual,
so it is assumed that persons using this book to perform maintenance and repairs on YAMAHA and
MBK scooters have a basic understanding of the mechanical concepts and procedures inherent in
scooter repair technology. Without such knowledge, attempted repairs or service to this model may
render it unfit to use and/or unsafe.
MBK INDUSTRIE is continually striving to improve all models manufactured. Modifications and
significant changes in specifications or procedures will be forwarded to all Authorized YAMAHA and
MBK dealers and will, where applicable, appear in future editions of this manual.
DOCUMENTATION TECHNIQUE
MBK INDUSTRIE
PARTICULARY IMPORTANT INFORMATION
This material is distinguished by the following notation :
The safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR
SAFETY IS INVOLVED!
Failure to follow WARNING instructions could result in severe injury or
death to the scooter operator, a bystander, or a person inspecting or
repairing the scooter.
A CAUTION indicates special precautions that must be taken to avoid
damage to the scooter.
A NOTE provides key information to make procedures easier or clearer.
NOTE:

HOW TO USE THIS MANUAL
CONSTRUCTION OF THIS MANUAL
This manual consists of chapters for the main categories of subjects. (See «illustrated symbols).
1st title 1This is a chapter with its symbol on the upper right of each page.
2nd title 2This title appears on the upper of each page on the left of the chapter symbol. (For
the chapter «Periodic inspection and adjustment» the 3rd title appears.)
3rd title 3This is a final title.
MANUAL FORMAT
All of the procedures in this manual are organized in a sequential, step-by-step format. The informa-
tion has been compiled to provide the mechanic with an easy to read, handy reference that contains
comprehensive explanations of all disassembly, repair, assembly, and inspections.
A set of particulary important procedure 4is placed between a line of asterisks " * " with each step
preceded by " •".
IMPORTANT FEATURES
• Data and a special tools are framed in a box preceded by a relevant symbol 5.
• An encircled numeral 6indicates a part name, and an encircled alphabetical letter data for an
alignement mark 7, the others being indicated by an alphabetical letter in a box 8.
• A condition of a faulty component will precede an arrow symbol and the course of action required
the symbol 9.
EXPLODED DIAGRAM
Each chapter provides exploded diagrams are before each disassembly section for ease in identifying
correct disassembly and assembly procedures.

ILLUSTRATED SYMBOLS
(REFER TO THE ILLUSTRATION)
Illustrated symbols Qto Ware designed as
thumb tabs to indicate the chapter’s number and
content.
QGeneral information
WSpecifications
EPeriodic inspection and adjustment
REngine
TCarburetion
YChassis
UElectrical
ITroubleshooting
Illustrated symbols Oto eare used to identify
the specifications appearing in the text.
OFilling fluid
PLubricant
{Special tool
}Tightening
qWear limit, clearance
wEngine speed
eΩ, V, A
Illustrated symbols rto [in the exploded
diagram indicate grade of lubricant and location
of lubrication point.
rApply engine oil
tApply gear oil
yApply molybdenum disulfide oil
uApply wheel bearing grease
iApply lightweight lithium-soap base
grease
oApply molybdenum disulfide grease
pApply locking agent (THREADLOCK ®)
[Use new one
INSP
ADJ
TRBL
SHTG
GEN
INFO
ENG
CHAS
CARB
ELEC
SPEC
T.R
QW
RE
TY
UI
OP
{}
qw
e
r
u
p[
ty
io

1
2
3
4
6
7
8
9
INDEX
SPECIFICATIONS
ENGINE OVERHAUL
CARBURETION
CHASSIS
ELECTRICAL
TROUBLESHOOTING
GENERALINFORMATION
PERIODIC INSPECTION
AND ADJUSTMENT
SPEC
ENG
CARB
CHAS
ELEC
TRBL
SHTG
GEN
INFO
INSP
ADJ
5
COOLING SYSTEM ENG

1
GEN
INFO

GEN
INFO
CHAPTER 1.
GENERAL INFORMATION
SCOOTER IDENTIFICATION ........................................................................ 1-1
VEHICLE IDENTIFICATION NUMBER .................................................... 1-1
ENGINE SERIAL NUMBER .....................................................................1-1
IMPORTANT INFORMATION ....................................................................... 1-2
ALL REPLACEMENT PARTS ................................................................. 1-2
GASKETS, OIL SEALS, AND O-RINGS ..................................................1-2
LOCK WASHERS/PLATES AND COTTER PINS .................................... 1-2
BEARINGS AND OIL SEALS ................................................................... 1-2
CIRCLIPS .................................................................................................1-3
SPECIAL TOOLS ...........................................................................................1-4

GEN
INFO
1-1
GENERAL INFORMATION
SCOOTER IDENTIFICATION
VEHICLE IDENTIFICATION NUMBER
The vehicle identification number Qis stamped
into the frame.
NOTE:
The vehicle identification number is used to
identify your scooter and may be used to register
your scooter with the licensing authority in your
state.
ENGINE SERIAL NUMBER
The engine serial number Qis stamped into the
crankcase.
NOTE:
The first three digits of these numbers are for
model identifications; the remaining digits are
the unit production number.
NOTE:
Designsand specificationsaresubject tochange
without notice.
SCOOTER IDENTIFICATION
햲
햲

GEN
INFO
1-2
IMPORTANT INFORMATION
IMPORTANT INFORMATION
ALL REPLACEMENT PARTS
1.Use only genuine parts for all replacements.
Use oil and/or grease recommended by MBK/
YAMAHA for assembly and adjustment. Other
brands may be similar in function and
appearance, but inferior in quality.
GASKETS, OIL SEALS, AND O-RINGS
1.All gaskets, seals and O-rings should be
replaced when an engine is overhauled. All
gaskets surfaces, oil seal lips and O-rings
must be cleaned.
2.Properlyoilall mating partsand bearingduring
reassembly. Apply grease to the oil seal lips.
LOCK WASHERS/PLATES AND COTTER
PINS
1.All lock washers/plates Qand 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.
BEARINGS AND OIL SEALS
1.Install the bearing(s) Qand oil seal(s) Wwith
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
lightweight lithium base grease to the seal
lip(s).Oil the bearingsliberally when installing.
Do not use compressed air to spin the
bearings dry. This causes damage to the
bearing surfaces.
CAUTION :