2015 YAMAHA YZ85 Fuel mix

INSTRUMENT AND CONTROL FUNCTIONS
4-3
4
EAU12944
Brake pedalThe brake pedal is located on the right
side of the motorcycle. To apply the
rear brake, press down on the brake
pedal.
EAU13183
Fuel tank capTo remove the fuel tank cap, turn it
counterclockwise, and then pull it off.
To install the fuel tank cap, insert it into
the tank opening, and then turn it
clockwise.
WARNING
EWA11092
Make sure that the fuel tank cap is
properly close d after fillin g fuel.
Leakin g fuel is a fire hazar d.
EAU41835
FuelThis motorcycle has been designed to
use a premixed fuel of gasoline and 2-
stroke engine oil. Always mix the gaso-
line and oil in a clean container before
filling the fuel tank.NOTICE
ECA15602
Always use fresh gasoline, an d fill
the fuel tank with a fresh mix just be-
fore ri din g. Do not use premixe d fuel
that is more than a few hours ol d.Mixin g g asoline an d 2-stroke en gine
oil
Pour 2-stroke engine oil into a clean
container, and then add gasoline. To
mix the fuel thoroughly, shake the con-
tainer from side to side.
1. Brake pedal
1. Fuel tank cap
U1SN83E0.book Page 3 Monday, September 8, 2014 2:36 PM

INSTRUMENT AND CONTROL FUNCTIONS
4-4
4
NOTICE
ECA15591
Use only unleaded g asoline. The use
of lead ed g asoline will cause severe
d amag e to internal en gine parts,
such as the piston rin gs as well as to
the exhaust system.
Your Yamaha engine has been de-
signed to use premium unleaded gas-
oline with a pump octane number
[(R+M)/2] of 91 or higher, or a research
octane number of 95 or higher. If
knocking (or pinging) occurs, use a
gasoline of a different brand.
If the recommended 2-stroke engine
oil is not available, use an equivalent
oil.NOTICE
ECA15552
Never mix two bran ds of 2-stroke
en gine oil in the same batch. Always
use the same type of oil to ensure
maximum en gine performance.
Shoul d it b e necessary to use a dif-
ferent oil b rand, b e sure to d rain the
fuel tank an d the car buretor float
cham ber of the ol d premixe d fuel
prior to filling with the new type.
Filling the fuel tank
Make sure there is sufficient gasoline in
the tank.
WARNING
EWA10882
Gasoline an d g asoline vapors are
extremely flamma ble. To avoi d fires
an d explosions an d to re duce the
risk of injury when refuelin g, follow
these instructions.1. Before refueling, turn off the en- gine and be sure that no one is sit-
ting on the vehicle. Never refuel
while smoking, or while in the vi-
cinity of sparks, open flames, or
1. 2-stroke engine oil
2. Gasoline
3. ContainerRecommen ded fuel:
Premium unleaded gasoline only
Recommen ded 2-stroke en gine oil:
See page 9-1.
Fuel tank capacity:
5.0 L (1.32 US gal, 1.10 Imp.gal)
Mixin g ratios ( gasoline to oil):
Break-in period: 15:1
After break-in: 30:1
1. Maximum fuel level
2. Fuel tank filler tube
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INSTRUMENT AND CONTROL FUNCTIONS
4-6
4
EAU41281
Fuel cockThe fuel cock supplies fuel from the
tank to the carburetor while filtering it
also.
The fuel cock has two positions:
OFF
With the lever in this position, fuel will
not flow. Always return the lever to this
position when the engine is not run-
ning.ON
With the lever in this position, fuel flows
to the carburetor. Normal riding is done
with the lever in this position.
EAU13641
Starter (choke) kno
bStarting a cold engine requires a richer
air-fuel mixture, which is supplied by
the starter (choke).
Move the knob in direction (a) to turn
on the starter (choke).
Move the knob in direction (b) to turn
off the starter (choke).
1. Arrow mark positioned over “OFF”
1. Arrow mark positioned over “ON”
1. Starter (choke) knob
U1SN83E0.book Page 6 Monday, September 8, 2014 2:36 PM

FOR YOUR SAFETY – PRE-OPERATION CHECKS
5-1
5
EAU15598
Inspect your vehicle each time you use it to make sure the vehicle is in safe operating condition. Always follow the inspection
and maintenance procedures and schedules described in the Owner’s Manual.
WARNING
EWA11152
Failure to inspect or maintain the vehicle properly increases the possibility of an acci dent or equipment damag e.
Do not operate the vehicle if you fin d any pro blem. If a pro blem cannot be corrected b y the proce dures provi ded in
this manual, have the vehicle inspecte d b y a Yamaha dealer.Before using this vehicle, check the following points:
ITEM CHECKS PAGE
Fuel • Check fuel level in fuel tank.
• Always use a fresh mixture of gasoline and oil.
• Check fuel line for leakage.
• Check fuel tank breather hose for obstructions, cracks or damage, and check
hose connection. 4-3, 4-5
Transmission oil • Check for leakage. 7-9
Coolant • Check coolant level.
• If necessary, add recommended coolant to specified level.
• Check cooling system for leakage. 7-10
Front brake • Check operation.
• If soft or spongy, have Yamaha dealer bleed hydraulic system.
• Check brake pads for wear.
• Replace if necessary.
• Check fluid level in reservoir.
• If necessary, add specified brake fluid to specified level.
• Check hydraulic system for leakage. 7-20, 7-20
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OPERATION AND IMPORTANT RIDING POINTS
6-3
6
EAU41505
Engine 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 durin g
service or while usin g the vehicle. If
you are not familiar with vehicle ser-
vice, have a Yamaha d ealer perform
service.1. Before starting the engine, 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 lower gears at moderate throttle
openings for five to eight minutes.
Stop the engine and check the spark plug condition (see page
7-8); 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 five
minutes. Then, very briefly shift to
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 five more minutes. Full
throttle and the higher gears may
be used, but sustained full-throttle
operation 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 specified mix. (See page 4-3.) 8. Start the engine and check the op-
eration of the motorcycle through-
out its entire operating range.
Stop the engine and check the
spark plug condition. Restart the
motorcycle and ride it for about 10
to 15 more minutes. The motorcy-
cle will now be ready to ride nor-
mally.
After the engine break-in period, thor-
oughly check the motorcycle for loose
parts, oil leakage and any other prob-
lems. Be sure to inspect and make ad-
justments thoroughly, especially cable
and drive chain slack and loose
spokes. In addition, check all fittings
and fasteners for looseness, and tight-
en if necessary.
NOTICE
ECA15561
 When any of the followin g parts
have been replaced , they must
b e broken in.
Cylin der or crankshaft:
A bout one hour of b reak-in op-
eration is necessary.
Piston, rin gs or transmission
g ears:
Recommen ded 2-stroke en gine oil:
See page 9-1.
Mixin g ratio ( gasoline to oil):
15:1
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SPECIFICATIONS
9-1
9
Dimensions:Overall length:YZ85 1821 mm (71.7 in)
YZ85F 1821 mm (71.7 in)
YZ85LW 1899 mm (74.8 in)
YZ85LWF 1899 mm (74.8 in)
Overall width:
758 mm (29.8 in)
Overall height: YZ85 1126 mm (44.3 in)
YZ85F 1126 mm (44.3 in)
YZ85LW 1156 mm (45.5 in)
YZ85LWF 1156 mm (45.5 in)
Seat height: YZ85 841 mm (33.1 in)
YZ85F 841 mm (33.1 in)
YZ85LW 873 mm (34.4 in)
YZ85LWF 873 mm (34.4 in)
Wheelbase:
YZ85 1257 mm (49.5 in)
YZ85F 1257 mm (49.5 in)
YZ85LW 1285 mm (50.6 in)
YZ85LWF 1285 mm (50.6 in)
Ground clearance: YZ85 330 mm (12.99 in)
YZ85F 330 mm (12.99 in)
YZ85LW 360 mm (14.17 in)
YZ85LWF 360 mm (14.17 in)Wei ght:Curb weight:
YZ85 71 kg (157 lb)
YZ85F 71 kg (157 lb)
YZ85LW 73 kg (161 lb)
YZ85LWF 73 kg (161 lb)
Engine:Engine type:
Liquid cooled 2-stroke
Cylinder arrangement:
Single cylinder
Displacement: 85 cm³
Bore × stroke:
47.5 × 47.8 mm (1.87 × 1.88 in)
Compression ratio:
8.1 : 1
Starting system: Kickstarter
Lubrication system: PremixEngine oil:Type:
YAMALUBE 2RTransmission oil:Type:
YAMALUBE 4 (10W-40) or SAE 10W-40
Oil change quantity: 0.50 L (0.53 US qt, 0.44 Imp.qt)Coolant quantity:Radiator (including all routes):
0.54 L (0.57 US qt, 0.48 Imp.qt)Air filter:Air filter element:Wet elementFuel:Recommended fuel:Premium unleaded gasoline only
Fuel tank capacity: 5.0 L (1.32 US gal, 1.10 Imp.gal)
Car buretor:Type × quantity:
PWK28 x 1Spark plu g(s):Manufacturer/model:
NGK/BR10EG
Spark plug gap: 0.5–0.6 mm (0.020–0.024 in)Clutch:Clutch type:Wet, multiple-discTransmission:Primary reduction ratio:
3.611 (65/18)
Final drive: Chain
Secondary reduction ratio: YZ85 3.428 (48/14)
YZ85F 3.428 (48/14)
YZ85LW 3.714 (52/14)
YZ85LWF 3.714 (52/14)
Transmission type:
Constant mesh 6-speed
Operation: Left foot operation
Gear ratio: 1st:2.454 (27/11)
2nd: 1.882 (32/17)
3rd:
1.529 (26/17)
4th: 1.294 (22/17)
U1SN83E0.book Page 1 Monday, September 8, 2014 2:36 PM