2003 YAMAHA YFM80R engine

8-39
EBU00303
Valve clearance adjustment
The correct valve clearance changes with use,
resulting in improper fuel/air supply or engine
noise. To prevent this, the valve clearance must
be adjusted regularly. This adjustment however,
should be left to a professional Yamaha service
technician.
EBU00304
Cam chain adjustment
The cam chain becomes loose with use, result-
ing in improper valve timing and engine noise.
To prevent this, the cam chain tensioner must
be adjusted regularly. This adjustment should be
left to a Yamaha service technician.
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8-53
EBU00570
Cable inspection and lubrication
w
Inspect cables frequently and replace if dam-
aged. Corrosion can result when the outer
covering of control cables becomes dam-
aged. Cables can also become frayed or
kinked. Operation of controls could be
restricted, which could cause an accident or
injury.
Lubricate the inner cables and the cable ends. If
the cables do not operate smoothly, ask a
Yamaha dealer to replace them.
Recommended lubricant:
Engine oil
5TH-9-61 8 4/17/02 4:46 PM Page 8-53

EBU00440
Troubleshooting chart
1. Fuel
Check if there is
fuel in the fuel
tank
2. Compression
Use electric starter
to see if there is
compression
3. Ignition
Remove plug and
check electrodes
WetWipe clean with dry
cloth
DryAttach plug cap and
ground to chassisUse electric
starterSpark weak
Spark goodIgnition system normal
No spark
Ask a Yamaha dealer to inspect
Adjust plug gap or
replace plug
There is compressonCompression normal
Ask a Yamaha dealer to inspectNo compression
There is fuelTurn the fuel
cock to “OFF”
Remove the
fuel hose from
the fuel cock.
Some fuelTurn the fuel
cock to “RES”Restart engine
No fuelSupply fuel
4. Battery
Use electric
starter
Engine turns
over quicklyBattery good
Engine turns
over slowlyCheck fluid, recharge,
check connections
Check fuel flow
Water or dirt
mixed in fuel
Turn the fuel
cock to “ON”No fuelFuel cock clogged
Clean the fuel filter
and the fuel tank
Clean fuel cock
8-73
5TH-9-61 8 4/17/02 4:46 PM Page 8-73

9-1
EBU00420
CLEANING AND STORAGE
A. CLEANING
Frequent, thorough cleaning of your machine
will not only enhance its appearance but will
improve its general performance and extend the
useful life of many components.
1. Before cleaning the machine:
a. Block off the end of the exhaust pipe to
prevent water entry. A plastic bag and
strong rubber band may be used.
b. Make sure the spark plug and all filler caps
are properly installed.
2. If the engine case is excessively greasy,
apply degreaser with a paint brush. Do not
apply degreaser to the wheel axles.
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9-5
6. Clean the seat with a vinyl upholstery
cleaner to keep the cover pliable and
glossy.
7. Automotive type wax may be applied to all
painted and chrome plated surfaces. Avoid
combination cleaner-waxes. Many contain
abrasives which may mar the paint or pro-
tective finish.
When finished, start the engine and let it
idle for several minutes.
w
Wet brakes may have reduced stopping abili-
ty, increasing the chance of an accident.
Test the brakes after washing. Apply the
brakes several times at slow speeds to let
friction dry out the linings.
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9-7
EBU00427
B. STORAGE
Long term storage (60 days or more) of your
machine will require some preventive proce-
dures to guard against deterioration. After thor-
oughly cleaning the machine, prepare for stor-
age as follows:
1. Fill the fuel tank with fresh fuel and add
fuel stabilizer (if available).
NOTE:
Use of fuel stabilizer eliminates the need to
drain the fuel system. Consult a Yamaha dealer
if the fuel system is to be drained instead.
2. Remove the spark plug, pour about one
tablespoon of SAE 10W30 or 20W40
motor oil in the spark plug hole and rein-
stall the spark plug. Ground the spark plug
wire and turn the engine over several times
to coat the cylinder wall with oil.
3. Lubricate all control cables.
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10-1
Model YFM80W
Dimensions:
Overall length 1,537 mm
Overall width 841 mm
Overall height 940 mm
Seat height 669 mm
Wheelbase 1,030 mm
Ground clearance 100 mm
Minimum turning radius 2,400 mm
Basic weight:
With oil and full fuel tank 116 kg
Engine:
Type Air-cooled 4-stroke, SOHC
Cylinder arrangement Single cylinder, forward-inclined
Displacement 79 cm
3
Bore × Stroke 47.0 ×45.6 mm
Compression ratio 9.6 : 1
Starting system Electric starter
Lubrication system Wet sump
EBU00428
SPECIFICATIONS
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10-2
10
MODEL YFM80W
Engine oil:
Type
Recommended engine oil classification: API Service SE, SF, SG type or higher
Quantity:
Periodic oil change 0.80 L
Total amount0.95 L
cC
Be sure to use motor oils that do not contain
anti-friction modifiers. Passenger car motor
oils (often labeled “ENERGY CONSERVING
II”)
contain anti-friction additives which will cause
clutch and/or starter clutch slippage, resulting
in reduced component life and poor engine
performance.
–20° 10° 20° 30° 40°
10W30
10W40
20W40
20W5050°C
0° –10°
5W30
15W40
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