spark plug YAMAHA YZ65 2021 Owners Manual

Table of contents
Location of important la bels ........... 1-1
Safety information ............................ 2-1
Description ....................................... 3-1
Left view ......................................... 3-1
Right view ....................................... 3-2
Controls and instruments ............... 3-3
Instrument an d control functions ... 4-1
Handlebar switch............................ 4-1
Clutch lever .................................... 4-1
Shift pedal ...................................... 4-2
Brake lever...................................... 4-2
Brake pedal .................................... 4-3
Fuel tank cap .................................. 4-3
Fuel ................................................. 4-4
Fuel tank breather hose.................. 4-6
Fuel cock ........................................ 4-7
Starter (choke) knob ....................... 4-7
Kickstarter ...................................... 4-8
Seat ................................................ 4-8
Adjusting the front fork ................... 4-9
Front fork bleeding ....................... 4-11
Adjusting the shock absorber assembly ................................... 4-12
Removable sidestand ................... 4-16
YPVS system ................................ 4-17
For your safety – pre-operation
checks ............................................... 5-1
Operation an d important ri din g
points ................................................ 6-1
Engine break-in .............................. 6-1
Starting and warming up a cold
engine ......................................... 6-3
Starting a warm engine .................. 6-3
Shifting ........................................... 6-4
Parking ........................................... 6-5
Perio dic maintenance an d
a d justment ........................................ 7-1
Periodic maintenance and lubrication chart .......................... 7-2
Checking the spark plug ................ 7-6 Transmission oil .............................. 7-7
Coolant ............................................ 7-8
Cleaning the air filter element ....... 7-10
Adjusting the carburetor ............... 7-12
Adjusting the engine idling
speed ......................................... 7-12
Adjusting the throttle grip free play ............................................ 7-13
Tires .............................................. 7-14
Spoke wheels ................................ 7-16
Adjusting the clutch lever free play ............................................ 7-16
Checking the brake lever free play ............................................ 7-17
Checking the shift pedal ............... 7-18
Checking the front and rear brake pads ................................. 7-18
Checking the brake fluid level ....... 7-19
Changing the brake fluid ............... 7-20
Drive chain slack ........................... 7-21
Cleaning and lubricating the drive chain ................................. 7-22
Checking and lubricating the
cables ........................................ 7-23
Checking and lubricating the throttle grip and cable ............... 7-23
Checking and lubricating the brake and clutch levers ............. 7-24
Checking and lubricating the
brake pedal ................................ 7-24
Lubricating the rear suspension.... 7-25
Lubricating the swingarm pivots ... 7-25
Checking the front fork ................. 7-26
Checking the steering ................... 7-26
Checking the wheel bearings ........ 7-27
Supporting the motorcycle ........... 7-27
Front wheel ................................... 7-28
Rear wheel .................................... 7-29
Troubleshooting ............................ 7-30
Troubleshooting chart ................... 7-31
Motorcycle care an d stora ge .......... 8-1
Matte color caution ......................... 8-1
Care................................................. 8-1
Storage............................................ 8-4
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Description
3-2
3
EAU63391
Right view
21345
9867
1. Spring preload adjuster (page 4-12)
2. Compression damping force adjuster (page 4-12)
3. Kickstarter (page 4-8)
4. Spark plug cap (page 7-6)
5. Bleed screw (page 4-11)
6. Coolant drain bolt (page 7-9)
7. Brake pedal (page 4-3)
8. Transmission oil drain bolt (page 7-7)
9. Transmission oil filler cap (page 7-7)
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Operation and important rid ing points
6-1
6
EAU15952
Read the Owner’s Manual carefully to
become familiar with all controls. If
there is a control or function you do not
understand, ask your Yamaha dealer.
WARNING
EWA10272
Failure to familiarize yourself with
the controls can lead to loss of con-
trol, which coul d cause an acci dent
or injury.
EAU41506
En gine break-in
WARNING
EWA10322
Failure to properly maintain the vehi-
cle or performin g maintenance ac-
tivities incorrectly may increase
your risk of injury or death during
service or while usin g the vehicle. If
you are not familiar with vehicle ser-
vice, have a Yamaha d ealer perform
service.
TIP
Before starting the engine for the first
time, the air filter must be lubricated.
(See page 7-10.)
En gine break-in proced ure
1. Fill the fuel tank with a break-in oil- fuel mixture as follows.
2. Start and warm up the engine. Check the operation of the con-
trols and the engine stop switch.
(See page 4-1.)
3. Operate the motorcycle in the low- er gears at moderate throttle
openings for 5 to 8 minutes. Stop
the engine and check the spark
plug condition (see page 7-6); it
will show a rich condition during
break-in.
4. Allow the engine to cool. Restart the engine and operate the motor-
cycle as in the step above for 5
minutes. Then, very briefly shift to
Recommen ded 2-stroke en gine oil:
YA M A L U B E 2 R
Mixin g ratio ( gasoline to oil):
15:1
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Operation and important ri din g points
6-2
6
the higher gears and check the
full-throttle response. Stop the en-
gine and check the spark plug.
5. After again allowing the engine to cool, restart and run the motorcy-
cle for 5 more minutes. Full throttle
and the higher gears may be used,
but sustained full-throttle opera-
tion should be avoided. Stop the
engine and check the spark plug
again.
6. Allow the engine to cool, remove the cylinder head and cylinder,
and inspect the piston and cylin-
der. Remove any high spots on
the piston with #600-grit wet
sandpaper. Clean all components
and carefully reassemble the cyl-
inder head and cylinder.
7. Drain the break-in oil-fuel mixture from the fuel tank and refill with
the normal oil-fuel mixture. (See
page 4-4.)
8. Start the engine and check its power delivery and throttle re-
sponse throughout all gear rang-
es. Stop the engine and check the
spark plug condition. It should be-
gin to lighten in color.
9. Restart the motorcycle and ride it for about 10 to 15 more minutes.
Stop the engine and check the
spark plug condition. (See page
7-6.)
10. Lastly, thoroughly check the mo- torcycle for loose parts, oil leak-
age and any other problems.
Check all fittings and fasteners
and tighten as necessary.
TIP
Be sure to inspect and make adjust-
ments thoroughly. In particular, check
control cable slack, drive chain slack
and for loose spokes.
Notes on en gine overhauls
If the following parts have been re-
placed, they must be broken in as fol-
lows.  Piston, rings or transmission
gears: 30 minutes of break-in op-
eration at half-throttle or less.
 Cylinder or crankshaft: 60 minutes
of break-in operation is necessary.
TIP
Observe the condition of the engine
carefully during break-in operation.
NOTICE
ECA10271
If any en gine trou ble shoul d occur
d urin g the en gine break-in perio d,
imme diately have a Yamaha dealer
check the vehicle.
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Periodic maintenance an d a djustment
7-3
7
10 *Rotor nut
(flywheel magneto) Tighten.
11 *
Kickstarter system Check idle gear for damage. Replace if necessary.
Check exhaust pipe and muffler for
carbon deposits.

12 *Exhaust system
Clean.
 Check crankshaft for carbon depositsand damage.13 *Crankshaft
Clean.
 


14 *
Carburetor Check carburetor settings and for
obstructions.
Adjust and clean. Check condition.
15Spark plug Clean and regap.
Replace.
 Check chain slack, alignment and
condition.
16 *Drive chain Adjust and thoroughly lubricate chain
with Yamaha chain and cable lube or
equivalent.
Replace.
NO. ITEM ROUTINE
After
break-in
Everyrace
Every
third race
Every
fifth race
As
required
7 *Clutch Check clutch housing, friction plates,
clutch plates and clutch springs for
wear or damage.
Adjust.
Replace.

8 *
Transmission Change the transmission oil. Check transmission for damage. Replace bearings.
9 *Shift forks, guide
bars, shift cam Check all parts for wear and damage. Replace if necessary.
UBR882E0.book Page 3 Wednesd
ay, February 26, 2020 11:39 AM

Periodic maintenance an d a djustment
7-6
7
EAU84450
Checkin g the spark plu g
The spark plug is an important engine
component, which is easy to check.
Since heat and deposits will cause any
spark plug to slowly erode, the spark
plug should be removed and checked
in accordance with the periodic main-
tenance and lubrication chart. In addi-
tion, the condition of the spark plug
can reveal the condition of the engine.
To remove the spark plu g
1. Remove the spark plug cap.
2. Remove the spark plug as shown, with a spark plug wrench available
at a Yamaha dealer. To check the spark plu
g
1. Check that the porcelain insulator around the center electrode of the
spark plug is a medium-to-light
tan (the ideal color when the vehi-
cle is ridden normally).
TIP
If the spark plug shows a distinctly dif-
ferent color, the engine could be oper-
ating improperly. Do not attempt to
diagnose such problems yourself. In-
stead, have a Yamaha dealer check
the vehicle.
2. Check the spark plug for electrodeerosion and excessive carbon or
other deposits, and replace it if
necessary.
3. Measure the spark plug gap with a wire thickness gauge and, if nec-
essary, adjust the gap to specifi-
cation.
1. Spark plug cap
1. Spark plug wrench
1
1
Specified spark plu g:
NGK/BR9ECM
1. Spark plug gap
Spark plu g g ap:
0.7–0.8 mm (0.028–0.031 in)
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Periodic maintenance an d a djustment
7-7
7
To install the spark plu
g
1. Clean the surface of the spark plug gasket and its mating sur-
face, and then wipe off any grime
from the spark plug threads.
2. Install the spark plug with the spark plug wrench, and then tight-
en it to the specified torque.
TIP
If a torque wrench is not available
when installing a spark plug, a good
estimate of the correct torque is 1/4…
1/2 turn past finger tight. However, the
spark plug should be tightened to the
specified torque as soon as possible.
3. Install the spark plug cap asshown.
EAU4144C
Transmission oil
The transmission must be checked for
oil leakage before each ride. If any
leakage is found, have a Yamaha deal-
er check and repair the motorcycle. In
addition, the transmission oil must be
changed at the intervals specified in
the periodic maintenance and lubrica-
tion chart.1. Start the engine, warm it up for several minutes, and then turn it
off.
2. Place the motorcycle on a level surface and hold it in an upright
position.
3. Place an oil pan under the trans- mission case to collect the used
oil.
4. Remove the transmission oil filler cap and its O-ring, and then re-
move the transmission oil drain
bolt and its gasket to drain the oil
from the transmission.
5. Install the drain bolt and its new gasket, and then tighten the bolt
to the specified torque.
Tightening torque:
Spark plug: 20 N·m (2.0 kgf·m, 15 lb·ft)
1. Spark plug cap
1
1. Transmission oil filler cap
2. O-ring
3. Transmission oil drain bolt
4. Gasket
1
2
43
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Periodic maintenance an d a djustment
7-31
7
EAU86410
Trou bleshootin g chart
1. FuelThere is enough fuel.
There is no fuel.
Check the ignition.
Supply fuel.The engine does not
start.
Check the ignition.
Open the throttle
halfway and try
starting the engine.
Wipe off with a dry
cloth and correct the
spark plug gap, or
replace the spark
plug(s).
2. IgnitionWet
Dry
There is compression.
There is no
compression.
The engine does not start.
Have a Yamaha dealer check the vehicle.
Have a Yamaha dealer check the vehicle.
The engine does not
start.
Check the
compression.Have a Yamaha
dealer check the
vehicle.
Remove the spark
plug and check
the electrodes.
Try starting the
engine.
Check the fuel level
in the fuel tank.
3. Compression
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Motorcycle care and stora ge
8-4
8
EAU86460
Stora ge
Always store the vehicle in a cool, dry
place. If necessary, protect it against
dust with a porous cover. Be sure the
engine and the exhaust system are
cool before covering the vehicle. If the
vehicle often sits for weeks at a time
between uses, the use of a quality fuel
stabilizer is recommended after each
fill-up.
NOTICE
ECA21170
 Storin g the vehicle in a poorly
ventilate d room or coverin g it
with a tarp, while it is still wet,
will allow water an d humi dity to
seep in an d cause rust.
 To prevent corrosion, avoi d
d amp cellars, sta bles ( because
of the presence of ammonia)
an d areas where stron g chemi-
cals are stored .
Long term stora ge
Before storing the vehicle long term (60
days or more): 1. Make all necessary repairs and perform any outstanding mainte-
nance.
2. Follow all instructions in the Care Section of this chapter.
3. Fill up the fuel tank and add fuel stabilizer according to product in-
structions.
4. Run the engine for 5 minutes to distribute treated fuel through the
fuel system.
5. For vehicles with a fuel cock: Turn the fuel cock lever to the off posi-
tion. 6. For vehicles with a carburetor: To
prevent fuel deposits from build-
ing up, drain the fuel in the carbu-
retor float chamber into a clean
container. Retighten the drain bolt
and pour the fuel back into the fuel
tank.
7. Use a quality engine fogging oil according to product instructions.
If engine fogging oil is not avail-
able, perform the following steps
for each cylinder:a. Remove the spark plug cap and spark plug.
b. Pour a teaspoonful of engine oil into the spark plug bore.
c. Install the spark plug cap onto the spark plug, and then place
the spark plug on the cylinder
head so that the electrodes are
grounded. (This will limit spark-
ing during the next step.)
d. Turn the engine over several times with the starter or kick-
starter. (This will coat the cylin-
der wall with oil.) WARNING!
To prevent d amage or injury
from sparkin g, make sure to
g roun d the spark plu g elec-
tro des while turning the en-
g ine over.
[EWA10952]
e. Remove the spark plug cap
from the spark plug, and then
install the spark plug and the
spark plug cap.
8. Lubricate all control cables, piv- ots, levers and pedals, as well as
the sidestand and centerstand (if
equipped).
9. Check and correct the tire air pressure, and then lift the vehicle
so that all wheels are off the
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11-1
11
Index
A
Air filter element, cleaning .................... 7-10
B
Brake and clutch levers, checking and
lubricating .......................................... 7-24
Brake fluid, changing ........................... 7-20
Brake fluid level, checking ................... 7-19
Brake lever ............................................. 4-2
Brake lever free play, checking ............ 7-17
Brake pedal ............................................ 4-3
Brake pedal, checking and lubricating .......................................... 7-24
C
Cables, checking and lubricating ......... 7-23
Carburetor, adjusting ........................... 7-12
Care ........................................................ 8-1
Clutch lever ............................................ 4-1
Clutch lever free play, adjusting ........... 7-16
Coolant ................................................... 7-8
D
Drive chain, cleaning and lubricating ... 7-22
Drive chain slack .................................. 7-21
E
Engine break-in ...................................... 6-1
Engine idling speed .............................. 7-12
Engine overheating............................... 7-32
Engine serial number............................ 10-1
Engine, starting a warm ......................... 6-3
Engine stop switch ................................. 4-1
F
Front and rear brake pads, checking ... 7-18
Front fork, adjusting ............................... 4-9
Front fork, bleeding .............................. 4-11
Front fork, checking ............................. 7-26
Fuel......................................................... 4-4
Fuel cock ................................................ 4-7
Fuel tank breather hose ......................... 4-6
Fuel tank cap.......................................... 4-3
H
Handlebar switch ................................... 4-1
I
Identification numbers.......................... 10-1
K
Kickstarter .............................................. 4-8
L
Labels, location ...................................... 1-1
M
Matte color, caution ............................... 8-1
P
Parking ................................................... 6-5 Part locations .......................................... 3-1
Periodic maintenance and lubrication
chart ..................................................... 7-2
R
Rear suspension, lubricating ................ 7-25
S
Safety defects, reporting (For CANADA customers) .......................................... 10-2
Safety information................................... 2-1
Seat......................................................... 4-8
Shifting .................................................... 6-4
Shift pedal............................................... 4-2
Shift pedal, checking ............................ 7-18
Shock absorber assembly, adjusting ... 4-12
Sidestand .............................................. 4-16
Spark plug, checking .............................. 7-6
Specifications ......................................... 9-1
Starter (choke) knob ............................... 4-7
Starting and warming up a cold engine ................................................... 6-3
Steering, checking ................................ 7-26
Storage ................................................... 8-4
Supporting the motorcycle ................... 7-27
Swingarm pivots, lubricating ................ 7-25
T
Throttle grip and cable, checking and lubricating ........................................... 7-23
Throttle grip free play, adjusting ........... 7-13
Tires ...................................................... 7-14
Transmission oil ...................................... 7-7
Troubleshooting .................................... 7-30
Troubleshooting chart........................... 7-31
V
Vehicle identification number ............... 10-1
W
Wheel bearings, checking..................... 7-27
Wheel (front).......................................... 7-28
Wheel (rear) ........................................... 7-29
Wheels .................................................. 7-16
Y
YPVS system ........................................ 4-17
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