fuel YAMAHA YZ85 2020 User Guide

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 lea d 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 mi-
nutes. 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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Operation and important rid ing points
6-3
6
EAU41308
Startin g an d warmin g up a
col d en gine
1. Turn the fuel cock lever to “ON”.
2. Shift the transmission into the
neutral position.
3. Turn the starter (choke) on and completely close the throttle. (See
page 4-7.)
4. Start the engine by pushing the kickstarter lever down.
5. When the engine is warm, turn the starter (choke) off.
TIP
The engine is warm when it responds
quickly to the throttle with the starter
(choke) turned off.
NOTICE
ECA11043
For maximum en gine life, never ac-
celerate har d when the en gine is
col d!
EAU16661
Startin g a warm en gine
Follow the same procedure as for
starting a cold engine with the excep-
tion that the starter (choke) is not re-
quired when the engine is warm.
Instead, start the engine with the throt-
tle slightly open.
TIP
If the engine does not start after sever-
al kicks, try again with the throttle 1/4
to 1/2 open.
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Operation and important rid ing points
6-5
6
EAU17192
Parkin g
When parking, stop the engine, and
then turn the fuel cock lever to “OFF”.
WARNING
EWA10312
Since the en gine an d exhaust
system can become very hot,
park in a place where pe destri-
ans or chil dren are not likely to
touch them an d b e burne d.
 Do not park on a slope or on soft
groun d, otherwise the vehicle
may overturn, increasin g the
risk of a fuel leak an d fire.
 Do not park near grass or other
flamma ble materials which
mi ght catch fire.
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Periodic maintenance an d a djustment
7-4
7
23 *Front fork Check operation and for oil leakage.
Adjust if necessary.
 Clean dust seal and lubricate with
lithium-soap-based grease.
Replace fork oil.
 Replace oil seals.
NO. ITEM ROUTINE
After
break-in
Everyrace
Every
third race
Every
fifth race
As
required
Check coolant level and for leakage.
17 *
Cooling system Check hoses for cracks or damage. Check radiator cap spring operation. Change coolant.
Every 2 years
Every year Check all chassis fitting and fasteners.
18
*Chassis fasteners
Correct or tighten if necessary.
19Air filter element Clean. Replace.
20 *Frame Clean and check for damage.

21
*Fuel line Clean and check for leakage.
22 *
Brakes Adjust lever position and pedal height.
Lubricate pivot points.
Check brake disk surface.
Check fluid level and for leakage.
Tighten brake disk bolts, caliper bolts,
master cylinder bolts and union bolts.
Replace brake pads.
 Replace brake fluid.
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Periodic maintenance an d a djustment
7-31
7
EAU25872
Trou bleshootin g
Although Yamaha motorcycles receive
a thorough inspection before shipment
from the factory, trouble may occur
during operation. Any problem in the
fuel, compression, or ignition systems,
for example, can cause poor starting
and loss of power.
The following troubleshooting charts
represent quick and easy procedures
for checking these vital systems your-
self. However, should your motorcycle
require any repair, take it to a Yamaha
dealer, whose skilled technicians have
the necessary tools, experience, and
know-how to service the motorcycle
properly.
Use only genuine Yamaha replace-
ment parts. Imitation parts may look
like Yamaha parts, but they are often
inferior, have a shorter service life and
can lead to expensive repair bills.
WARNING
EWA15142
When checkin g the fuel system, d o
not smoke, an d make sure there are
no open flames or sparks in the ar-
ea, inclu din g pilot li ghts from water
heaters or furnaces. Gasoline or
g asoline vapors can i gnite or ex-
plo de, causin g severe injury or prop-
erty damag e.
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Periodic maintenance an d a djustment
7-32
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
UB4B81E0.book Page 32 Friday, March 1, 2019 2:54 PM

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 store d.
Lon g 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 turnin g 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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Specifications
9-1
9
Dimensions:
Overall length:1820 mm (71.7 in) (YZ85, YZ85L)
1895 mm (74.6 in) (YZ85LW, YZ85LWL)
Overall width: 760 mm (29.9 in)
Overall height:
1145 mm (45.1 in) (YZ85, YZ85L)
1175 mm (46.3 in) (YZ85LW, YZ85LWL)
Seat height:
840 mm (33.1 in) (YZ85, YZ85L)
870 mm (34.3 in) (YZ85LW, YZ85LWL)
Wheelbase:
1255 mm (49.4 in) (YZ85, YZ85L)
1285 mm (50.6 in) (YZ85LW, YZ85LWL)
Ground clearance: 330 mm (12.99 in) (YZ85, YZ85L)
360 mm (14.17 in) (YZ85LW, YZ85LWL)
Wei ght:
Curb weight:
73 kg (161 lb) (YZ85, YZ85L)
75 kg (165 lb) (YZ85LW, YZ85LWL)
Engine:
Combustion cycle:
2-stroke
Cooling system: Liquid cooled
Number of cylinders:
Single cylinder
Displacement: 85 cm³
Bore × stroke:
47.5 × 47.8 mm (1.87 × 1.88 in)
Starting system:
Kickstarter
Engine oil:
Engine oil:
YAMALUBE 2R
Recommended brand:
Transmission oil:
Type:
Motor oil SAE 10W-30 type SE or higher or
Gear oil SAE 85W GL-3
Quantity:
0.50 L (0.53 US qt, 0.44 Imp.qt)
Coolant quantity:
Radiator (including all routes): 0.55 L (0.58 US qt, 0.48 Imp.qt)
Fuel:
Recommended fuel:Unleaded gasoline (E10 acceptable)
Octane number (RON): 98
Fuel tank capacity:
5.0 L (1.3 US gal, 1.1 Imp.gal)
Car buretor:
Type × quantity:
PWK28 × 1
Drivetrain:
Gear ratio:
1st:
2.455 (27/11)
2nd:
1.882 (32/17)
3rd: 1.529 (26/17)
4th: 1.294 (22/17)
5th:
1.130 (26/23)
6th: 1.000 (25/25)
Front tire:
Type:
With tube
Size: 70/100-17 40M (YZ85, YZ85L)
70/100-19 42M (YZ85LW, YZ85LWL)
Manufacturer/model: DUNLOP/MX3SF
Rear tire:
Type:
With tube
Size: 90/100-14 49M (YZ85, YZ85L)
90/100-16 52M (YZ85LW, YZ85LWL)
Manufacturer/model: DUNLOP/MX3S
Front brake:
Type:
Hydraulic single disc brake
Rear brake:
Type:
Hydraulic single disc brake
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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 ............................ 7-21
Brake fluid level, checking .................... 7-20
Brake lever .............................................. 4-2
Brake lever free play, checking............. 7-18
Brake pedal............................................. 4-3
Brake pedal, checking and lubricating ........................................... 7-25
C
Cables, checking and lubricating ......... 7-23
Carburetor, adjusting ............................ 7-12
Care ........................................................ 8-1
Clutch lever ............................................. 4-1
Clutch lever free play, adjusting ........... 7-17
Coolant ................................................... 7-8
D
Drive chain, cleaning and lubricating .... 7-23
Drive chain slack................................... 7-21
E
Engine break-in....................................... 6-1
Engine idling speed .............................. 7-13
Engine overheating ............................... 7-33
Engine serial number ............................ 10-1
Engine, starting a warm .......................... 6-3
Engine stop switch ................................. 4-1
F
Front and rear brake pads, checking.... 7-19
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 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 ............................................. 4-15
Spark plug, checking ............................. 7-6
Specifications ......................................... 9-1
Starter (choke) knob ............................... 4-7
Starting and warming up a cold engine .................................................. 6-3
Steering, checking................................ 7-27
Storage ................................................... 8-4
Supporting the motorcycle................... 7-28
Swingarm pivots, lubricating ................ 7-26
T
Throttle grip and cable, checking and lubricating .......................................... 7-24
Throttle grip free play, adjusting........... 7-13
Tires ...................................................... 7-14
Transmission oil ..................................... 7-7
Troubleshooting ................................... 7-31
Troubleshooting chart .......................... 7-32
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 ........................................ 4-16
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