Yamaha VMX12H Manual

VMXl2N,
NC~K, KC

LIT - 1 161 6 - 1 0-1 2

FOREWORD
This Supplementary Service Manual has been prepared to introduce new service and data
for the VMX12H/VMX12HC. For complete service information procedures
it is necessary to
use this Supplementary Service Manual together with the following manual.
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VMX12N SERVICE MANUAL:2WE - 28197 - 10
VMXl2F SUPPLEMENTARY SERVICE MANUAL:2WE
- 28197 - 11
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VMX 12H/VMX12HC
SUPPLEMENTARY
SERVICE
MANUAL
01995 by Yamaha Motor Co. Ltd.
1st Edition, July 1995
All rights resewed.
Any reprinting or unauthorized use
without the written permission
of
Yamaha Motor Co., Ltd.
is expressly prohibited.

NOTICE ,
This model has been designed and manufactured to perform within certain specifications
in regard to performance and emissions. Proper service with the correct tools in neces -
sary to ensure that the motorcycle will operate as designed. If there is any question about
information changes that apply to this model. This policy is intended to provide the cus
-
tomer with the most satisfaction from his motorcycle and to conform with federal envi -
a service procedure, it is imperative that you contact a Yamaha dealer for any service
, ronmental quality objectives.
NOTE:
For USA, California:
This Service Manual contains information regarding periodic maintenance to the emission
control system. Please read this material carefully.
PARTICULARY IMPORTANT INFORMATION
This material is distinguished by the following notation.
a SAFETY IS INVOLVED!
The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR
Failure to follow WARNING instructions could result
in severe injury or
death to the motorcycle operator, a bystander, or a person inspecting
or repairing the motorcycle.
A CAUTION indicates special precautions that must be taken to avoid
damage to the motorcycle.
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 sym-
bo Is "
1st title This is a chapter with its symbol on the upper right of each page.
2nd title This 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.)
This is a final title.
3rd title
MANUAL FORMAT
All of the procedures in this manual are organized in a sequential, step - by - step format. The
information has been compiled to provide the mechanic with an easy to read,
handy refer -
ence that contains comprehensive explanations of all disassembly, repair, assembly, and
inspections.
A set of particularly important procedure is placed between a line of asterisks
each procedure preceded by
IMPORTANT FEATURES
Data and a special tool are framed in a box preceded by a relevant symbol
An encircled numeral indicates a part name, and an encircled alphabetical letter data or
A condition of a faulty component will precede an arrow symbol and the course of action
an alignment mark the others being indicated by an alphabetical letter in a box
n required
EXPLODED DIAGRAM
Each chapter provides exploded diagrams before each disassembly section for ease in identi -
fying correct disassembly and assembly procedures.
-
- -
....
........ ............................
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8
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EB003000
ILLUSTRATED SYMBOLS
Illustrated symbols to are printed on
top right of each page and indicatethe sub
-
ject of each chapter.
General information
Specifications
Periodic inspections and adjustments
Engine
Cooling system
Carburetion
Chassis
Electrical
Troubleshooting
Illustrated symbols to are used to
identify the specifications appearing in the
text.
Filling fluid
Lubricant
Special tool
@Wear limit, clearance
Engine speed
V, A
Illustratedsymbols to in the exploded
diagrams indicate the types
of lubricants
and lubrication points.
Apply engine oil
Apply gear oil
Apply wheel bearing grease
Apply lightweight lithium - soap base grease
Apply molybdenum disulfide grease
Illustrated symbols to in the exploded
diagrams indicate the where
to apply locking
agent and when to install new parts
Apply locking agent
Replace
Apply molybdenum disulfide oil

. - .
CONTENTS
GENERAL INFORMATION .............................................................................. 1
MOTORCYCLE IDENTIFICATION
............................................................ 1
VEHICLE IDENTIFICATION NUMBER
................................................ 1
FRAME SERIAL NUMBER .................................................................. 1
ENGINE SERIAL NUMBER ................................................................. 1
SPECIAL TOOLS .....................................................................................
2
SPECIFICATIONS ............................................................................................ 3
GENERAL SPECIFICATIONS .................................................................. 3
MAINTENANCE SPECIFICATIONS ........................................................ 3
ENGINE ............................................................................................... 3
ELECTRICAL ........................................................................................ 4
PERIODIC INSPECTION AND ADJUSTMENT ................................................ 5
ENGINE .................................................................................................... 5
ENGINE OIL REPLACEMENT .............................................................. 5
ENGINE OVERHAUL ...................................................................................... 7
INSPECTION AND REPAIR ..................................................................... 7
CRANKSHAFT AND CONNECTING ROD .......................................... 7
BALANCER SHAFT ........................................................................... 11
MIDDLE GEAR SERVICE
....................................................................... 13
CHASSIS ........................................................................................................ 14
SHAFT DRIVE ......................................................................................... 14

GEN
MOTORCYCLE IDENTIFICATION
GENERAL INFORMATION
MOTORCYCLE IDENTIFICATION
VEHICLE IDENTIFlCATlON NUMBER
The vehicle identification number is
stamped into the right side of
the steering
pipe.
Starting serial number:
JYA2WEE0 TA050101 (USA)
JYA2WFC0 TA012101 (California)
The vehicle identification number is used to
identify your motorcycle and may be used
to register your motorcycle
with the licens -
ing authority in your state.
FRAME SERIAL NUMBER
The frame serial number is stamped into
the right side of the steering pipe.
Starting serial number:
1 2EN - 042101 (EUR)
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NOTE:
The first three digits of these numbers are
for model identifications; the remaining
digits are
the unit production number.
ENGINE SERIAL NUMBER
The engine serial number is stamped
into
the crankcase.
Starting serial number:
2WE
- 050101 (USA)
2WF
- 012101 (California)
I
2EN - 042101 (EUR)
NOTE:
The first three digits of these numbers are
for model identification; the remaining
digits are the unit production number.
Designs and specifications are subject to
change without notice.
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SPECIAL TOOLS GEN
SPECIAL TOOLS
Refer to the list provided to avoid errors
The proper special tools are necessary for
complete and accurate tune
- up and assem -
bly. Using the correct special tool will help
prevent damage caused by the use of
improper tools or improvised techniques.
The shape and part number used for the
special tool differ by country,
so two types
are provided.
FOR ENGINE SERVICE
when placing an order.
P/N. 90890 -
YM -
Except for
US, CDN
Oil filter wrench
YU - 38411
P/N 1 426
This tool is used to remove and install the oil
I filter.
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/ -
Model
Model code:
Engine starting number:
Vehicle identification number:
Frame starting number:
Basic weight:
With
oil and full fuel tank
GENERAL SPECIFICATIONS/
MAINTENANCE SPECIFICATIONS
VMX12
3JPM (USA)
3JPN (California)
3LRA (EUR)
2WF
- 012101 (California)
JYA2WEE0*TA050101 (USA)
JYA2WFC0
* TA0 12 1 0 1 ( California)
2WE
- 050101 (USA)
2EN
- 042101 (EUR)
2EN
- 042101 (EUR)
283 kg (624
Ib) (USA)
284 kg (626
Ib) (California)
281 kg (620
Ib) (EUR)
SPECIFICATIONS
GENERAL SPECIFICATIONS
MAINTENANCE SPECIFICATIONS
ENGINE
Model
Carbu
I. D. Mark
Main jet
Main air jet
Jet needle
Needle jet
Pilot jet
Pilot air jet
Pilot screw
Pilot outlet
Bypass
1
Bypass 2
Bypass 3
Valve seat size
Starter jet
Starter jet
Throttle valve size
Fuel level
Engine idling speed
Vacuum pressure at idling speed
(N.J)
(P.J)
(P.A.J.
1 )
(PS)
(P.O)
(B.P.l)
(B.P.2)
(B.P.3)
(V.S)
(G.S.1)
(G.S.2)
(Th.V)
(F.L)
VMX12
1FK 02 (USA), 2WF 02 (California),
3LR 01 (EUR)
#152.5 (USA, California), #150 (EUR)
82.0
5EZ43-1 (USA), 5EZ50-1 (California),
5EZ19-3 (EUR)
Y
- 0
#37.5 (USA, California), #42.5 (EUR)
#90 (USA),#100(California), #95 (EUR)
2
- 1/4 (USA), 3 (California), 2 - 1/2 (EUR)
0.9
0.8
0.8
0.9
1.5
#45
#0.8
#125 (USA, EUR), #130 (California)
15
~ 17 mm (0.59 ~ 0.66 in)
950 ~ 1,050 r/min (USA, EUR),
1,050 ~ 1,150 r /min (California)
26.7 kPa (200 mmHg, 7.87 in Hg) (USA, EUR)
33.3 kPa (250 mmHg, 9.84
in Hg) (California)
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