Yamaha XZ550RJ 1982 User manual

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YAMAHA
XZ550RJ
SERVICE MANUAL
11H-28197-10

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FEATURES
XZ550RJ
Liquid-cooled V-Twin
The 70° V-Twin engine is liquid-cooled to maintain the best operating temperature range. The cooling system
features an aluminum-corrugate radiator which is extremely light and exhibits excellent heat-dissipating char-
acteristics. An automatically activated electric fan pulls air through the radiator in heavy-traffic situations. The
system has an automotive-type expansion and recovery tank which makes airspace in the radiator unneces-
sary and virtually eliminates coolant loss on even the hottest days. A thermostatic valve mounted in the engine
block provides quick warmups and stable coolant temperature.

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YICS
To increase fuel economy through more efficient combustion, the engine is equipped with the patented Ya-
maha Induction Control System (YICS). In this configuration, the YICS consists of a chamber linked to the in-
take manifold by a tube. Upon intake, the vacuum in the manifold creates a vacuum in the chamber; when the
intake valve closes, the chamber draws in some air-fuel mixture. When the intake valve reopens, the mixture
in the chamber shoots back out through the angled tube and into the cylinder, mixing with and swirling the
main intake charge. The swirling charge is then compressed and ignited, burning more completely and produc-
ing more power than that of a conventional engine.
INTAKE SYSTEM AND YICS

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LIQUID COOLING SYSTEM
Downdraft carb
The induction system on this motorcycle features downdraft carburetion. The 34 mm (1.34 in) Venturis are
positioned so that the incoming air takes a virtually straight path through the carbs and the intake manifolds to
the combustion chambers; intake efficiency is remarkably high. An accelerator pump is installed in the carbu-
retor assembly to eliminate hesitation when the throttle is opened at low engine speeds. A fuel pump delivers
gas from the tank to the float bowls, and a regulator sends excess fuel through a circuit back to the fuel pump
inlet.
DOHC 4-valve heads
Each cylinder head has dual overhead camshafts, and each camshaft acts directly on top of the valves; there
are no pushrods or rocker arms. Both heads have four valves, two intake and two exhaust, instead of one in-
take and one exhaust valve. By using two slightly smaller valves in place of each large valve, port area is sig-
nificantly increased. This provides a much greater volume of mixture and exhaust flow. In addition, the smaller,
lighter valves are easier to control at high engine speeds; the valves can follow the cam profiles more closely
to resist "floating" and allow a 9,500 r/min red line.

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Chassis bits
The "hang-support" frame on this motorcycle allows a lower engine placement and center of gravity while pro-
viding excellent rigidity for precise handling. Cornering clearance is also enhanced. The trailing-axle front sus-
pension performs superbly. The axle placement helps to maintain a short wheelbase, allowing quick, sporty
handling. Yamaha's proven Monoshock rear suspension provides the excellent handling and comfort charac-
teristics for which it is famous. The spring preload is adjustable to five settings.
FRAME AND MONOCROSS SUSPENSION SYSTEM

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NOTICE
This manual was written by the Yamaha Motor Company primarily for use by Yamaha dealers and their quali-
fied 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 motorcycles have a hasic under-
standing of the mechanical concepts and procedures inherent to motorcycle repair technology. Without such
knowledge, attempted repairs or service to this model may render it unfit to use and/or unsafe.
This model has been designed and manufactured to perform within certain specifications in regard to perform-
ance and emissions. Proper service with the correct tools is necessary to ensure that the motorcycle will oper-
ate as designed. If there is any question about a service procedure, it is imperative that you contact a Yamaha
dealer for any service 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 environmental quality objec-
tives.
Yamaha Motor Company, Ltd. is continually striving to improve all models manufactured by Yamaha. Modifica-
tions and significant changes in specifications or procedures will be forwarded to all Authorized Yamaha deal-
ers and will, where applicable, appear in future editions of this manual.
NOTE:
This Service Manual contains information regarding periodic maintenance to the emission control system for
the XZ550RJ. Please read this material carefully.
Particularly important information is distinguished in this manual by the following notations:
NOTE: A NOTE provides key information to make procedures easier or clearer.
CAUTION: A CAUTION indicates special procedures that must be followed to avoid damage to the motorcy-
cle.
WARNING: A WARNING indicates special procedures that must be followed to avoid injury to a motorcycle
operator or person inspecting or repairing the motorcycle.
SERVICE DEPT.
INTERNATIONAL DIVISION
YAMAHA MOTOR CO., LTD.

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CHAPTER 1. GENERAL INFORMATION
MOTORCYCLE IDENTIFICATION………………………………………………………………………………..... 8
Frame serial number……………………………………………………………………………………….. 8
Engine serial number………………………………………………………………………………………. 8
Vehicle identification number…………………………………………………………………………….. 8
SPECIAL TOOLS……………………………………………………………………………………………………... 9
For tune-up…………………………………………………………………………………………………… 9
For engine service………………………………………………………………………………………….. 9
For chassis service…………………………………………………………………………………………. 12
For middle gear service……………………………………………………………………………………. 12
For shaft drive service……………………………………………………………………………………... 13
For electrical components………………………………………………………………………………… 13

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MOTORCYCLE IDENTIFICATION
Frame serial number
The frame serial number is stamped into the right
side of the steering head pipe.
1. Frame serial number
Engine serial number
The engine serial number is stamped into the ele-
vated part of the right rear section of the engine.
Starting serial number:
XZ550RJ 11H-000101
NOTE
The first three digits of these numbers are for model
identification; the remaining digits are the unit pro-
duction number.
1. Engine serial number
Vehicle identification number
The vehicle identification number is on the left side
of the steering head pipe.
1. Vehicle identification number
GENERAL INFORMATION

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SPECIAL TOOLS
The proper special tools are necessary for complete
and accurate tune-up and assembly. Using the cor-
rect special tool will help prevent damage caused by
the use of improper tools or improvised techniques.
For tune-up
Inductive tachometer (P/N YU-08036)
Inductive timing light (P/N YU-08037)
Fuel level gauge (P/N YM-01312)
Cooling system tester (P/N YU-24460)
Compression gauge (P/N YU-33223)
Compression gauge
12 mm (0.47 in) adapter (P/N YU-33223-3)
Vacuum gauge (P/N YU-08030)
This gauge is needed for carburetor synchronization
For engine service
Universal clutch holder
(P/N YM-91042)
This tool is used to hold the clutch when removing
or installing the clutch boss locknut
Tappet adjusting tool (P/N YM-28899)
This tool is necessary to replace valve adjusting
pads.
Valve spring compressor
(P/N YM-04019)
This tool must be used for removing and installing
the valve assemblies
Vavle guide remover
(P/N YM-04064)
This must be used to remove the valve guides

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Valve guide reamer
(P/N YM-04066)
This must be used when replacing the valve guide.
Valve guide installer
(P/N YM-04065)
This tool is needed for proper installation of the
valve guides.
Valve seat cutter set
(P/N YM-91043)
This tool is needed to resurface the valve seat.
Flywheel puller
(P/N YU-33270)
This tool is used for removing the flywheel
8mm (0,3 in) wrench adapter
(P/N YM-28897)
This tool is used to loosen or tighten the cylinder
head securing nut.
Water pump seal installer
(P/N YM-33221)
This tool is needed for proper installation of the wa-
ter pump seal.