2020 YAMAHA YZ85 ignition

Instrument and control functions
4-5
4 Gasoline
This model’s engine is designed to use
premium unleaded gasoline with a
pump octane number [(R+M)/2] of 91
or higher, or a research octane number
(RON) of 95 or higher. If knocking or
pinging occurs, try a gasoline of a dif-
ferent brand.
NOTICE
ECA15591
Use only unlea
ded g asoline. The use
of lea ded 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.
Gasohol
There are two types of gasohol: gaso-
hol containing ethanol and that con-
taining methanol. Gasohol containing
ethanol can be used if the ethanol con-
tent does not exceed 10% (E10). Gas-
ohol containing methanol should not
be used as it can cause engine or fuel
system problems.
Fillin g the fuel tank
WARNING
EWA10882
Gasoline an d gasoline 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
other sources of ignition such as
the pilot lights of water heaters
and clothes dryers.
2. Do not overfill the fuel tank. Stop filling when the fuel reaches the
bottom of the filler tube. Because
fuel expands when it heats up,
heat from the engine or the sun
can cause fuel to spill out of the
fuel tank.
3. Wipe up any spilled fuel immedi- ately. NOTICE: Immediately
wipe off spille d fuel with a clean,
d ry, soft cloth, since fuel may
d eteriorate painte d surfaces or
plastic parts.
[ECA10072]
4. Be sure to securely close the fuel tank cap.
WARNING
EWA15152
Gasoline is poisonous an d can cau-
se injury or death. Han dle gasoline
with care. Never siphon gasoline by
mouth. If you shoul d swallow some
g asoline or inhale a lot of gasoline
vapor, or get some g asoline in your
eyes, see your doctor imme diately. If
g asoline spills on your skin, wash
1. Maximum fuel level
2. Fuel tank filler tube
UB4B81E0.book Page 5 Friday, March 1, 2019 2:54 PM

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.
UB4B81E0.book Page 31 Friday, March 1, 2019 2:54 PM

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