Yamaha Wr 450 F Owners Manual

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GEN
INFO
IMPORTANT INFORMATION
EC136000
CIRCLIPS
1. All circlips should be inspected carefully
before reassembly. Always replace pis-
ton pin clips after one use. Replace dis-
torted circlips. When installing a circlip
1, make sure that the sharp-edged cor-
ner 2 is positioned opposite to the thrust
3 it receives. See the sectional view.
4Shaft 

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GEN
INFO
CHECKING OF CONNECTION
EC1C0001
CHECKING OF CONNECTION
Dealing with stains, rust, moisture, etc. on the
connector.
1. Disconnect:
Connector
2. Dry each terminal with an air blower.
3. Connect and disconnect the connector
two or three times.
4. Pull the lead to check that it will not come
off.
5. If the terminal comes off, bend up the pin
1 and reinsert the terminal into the con-
nector.
6. Connect:
Connector
NOTE:
The two connectors “click” together.
7. Check for continuity with a...

GEN
INFO
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EC140001
SPECIAL TOOLS
The proper special tools are necessary for complete and accurate tune-up and assembly. 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. Refer to the list provided to avoid errors when placing an order.
NOTE:
For U.S.A. and Canada, use part number starting with “YM-”, “YU-” or “ACC-”.
For others, use...

GEN
INFO
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SPECIAL TOOLS
YM-01442, 90890-01442 Fork seal driver
This tool is used when install the fork oil seal.YM-01442 90890-01442
YU-3112-C, 90890-03112 Yamaha pocket tester
Use this tool to inspect the coil resistance, output 
voltage and amperage.YU-3112-C 90890-03112
YU-8036-B
90890-03113Inductive tachometer
Engine tachometer
This tool is needed for observing engine rpm.YU-8036-B 90890-03113
YM-33277-A, 90890-03141 Timing light
This tool is necessary for checking ignition timing.YM-33277-A...

GEN
INFO
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SPECIAL TOOLS
YM-04141, 90890-04141 Rotor puller
This tool is used to remove the flywheel magneto.YM-04141 90890-04141
YM-34487
90890-06754Dynamic spark tester
Ignition checker
This instrument is necessary for checking the ignition 
system components.YM-34487 90890-06754
ACC-QUICK-GS-KT
90890-85505Quick gasket
 
YAMAHA Bond No. 1215
This sealant (Bond) is used for crankcase mating 
surface, etc.ACC-QUICK-GS-KT 90890-85505
Part number Tool name/How to use Illustration 

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GEN
INFO
CONTROL FUNCTIONS
EC150000
CONTROL FUNCTIONS
MAIN SWITCH
Functions of the respective switch positions
are as follows:
ON:
The engine can be started only at this position.
OFF:
All electrical circuits are switched off.
Main switch indicator light
The main switch 1 is equipped with an indica-
tor light 2 to avoid forgetting to turn it off. This
light functions as follows.
It lights up with the main switch “ON”.
It goes out when the engine increases its
speed after being started.
It...

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GEN
INFO
CONTROL FUNCTIONS
EC152000
CLUTCH LEVER
The clutch lever 1 is located on the left han-
dlebar; it disengages or engages the clutch.
Pull the clutch lever to the handlebar to disen-
gage the clutch, and release the lever to
engage the clutch. The lever should be pulled
rapidly and released slowly for smooth starts.
EC153000
SHIFT PEDAL
The gear ratios of the constant-mesh 5 speed
transmission are ideally spaced. The gears
can be shifted by using the shift pedal 1 on
the left side of the...

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GEN
INFO
CONTROL FUNCTIONS
EC157000
REAR BRAKE PEDAL
The rear brake pedal 1 is located on the right
side of the machine. Press down on the brake
pedal to activate the rear brake.
FUEL COCK
The fuel cock supplies fuel from the tank to
carburetor and also filters the fuel. The fuel
cock has three positions:
OFF:With the lever in this position fuel will not
flow. Always return the lever to this posi-
tion when the engine is not running.
ON: With the lever in this position fuel flows to
the...

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GEN
INFO
LIGHTS SWITCH
The lights switch 1 is located on the handle-
bar.
EC15F000
VALVE JOINT
This valve joint 1 prevents fuel from flowing
out and is installed to the fuel tank breather
hose.
CAUTION:
In this installation, make sure the arrow
faces the fuel tank and also downward.
SPARK PLUG WRENCH
This spark plug wrench 1 is used to remove
and install the spark plug.
1
1
NIPPLE WRENCH
This nipple wrench 1 is used to tighten the
spoke.
CONTROL FUNCTIONS 

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GEN
INFO
FUEL
Always use the recommended fuel as stated
below. Also, be sure to use new gasoline the
day of a race.
CAUTION:
Use only unleaded gasoline. The use of
leaded gasoline will cause severe damage
to the engine internal parts such as valves,
piston rings, and exhaust system, etc.
NOTE:
If knocking or pinging occurs, use a different
brand of gasoline or higher octane grade.
WARNING
For refueling, be sure to stop the engine
and use enough care not to spill any fuel.
Also be sure to avoid...