Yamaha YZ 2018 Series, Owner'S Service Manual, Page: 32 / 402

STARTING AND BREAK-IN
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EASB29B040
STARTING AND BREAK-IN
EASB29B041
FUEL
Always use the recommended fuel as stated
below. Also, be sure to use new gasoline the
day of a race.
ECA
NOTICE
Use only unleaded gasoline. The use of
leaded gasoline will cause severe damage
to the engine internal parts such as valves,
piston rings, and exhaust system, etc.
TIP
Your Yamaha engine has been designed to use
premium unleaded gasoline with a pump oc-
tane number [(R+M)/2] of 91 or higher, or a re-
search octane number of 95 or higher. If
knocking (or pinging) occurs, use a gasoline of
a different brand.
EWA
WARNING
• For refueling, be sure to stop the engine
and use enough care not to spill any fuel.
Also be sure to avoid refueling close to a
fire.
• Refuel after the engine, exhaust pipe, etc.
have cooled off.
Gasohol
There are two types of gasohol: gasohol con-
taining ethanol and that containing methanol.
Gasohol containing ethanol can be used if the
ethanol content does not exceed 10 %. Gasohol
containing methanol is not recommended by
Yamaha because it can cause damage to the
fuel system or vehicle performance problems.
EASB29B042
HANDLING NOTE
EWA
WARNING
Never start or run the engine in a closed ar-
ea. The exhaust fumes are poisonous; they
can cause loss of consciousness and death
in a very short time. Always operate the ma-
chine in a well-ventilated area.
ECA
NOTICE
• If the throttle is open the air/ fuel mixture
may be too lean for the engine to start.
• Before starting the machine, perform the
checks in the pre-operation check list.
EASB29B043
AIR FILTER MAINTENANCE
According to “CLEANING THE AIR FILTER
ELEMENT” section in the CHAPTER 3, apply
the Yamaha foam air filter oil or other quality
foam air filter oil to the element. (Excess oil in
the element may adversely affect engine start-
ing.)
EASB29B044
STARTING A COLD ENGINE
ECA
NOTICE
For maximum engine life, never accelerate
hard when the engine is cold!
In order for the ignition circuit cut-off system to
enable starting, one of the following conditions
must be met:
• The transmission is in the neutral position.
• The transmission is in gear with the clutch le-
ver pulled.
1. Pull the starter knob/idle screw “1” to its full
length.
TIP
When the ambient temperature is 15 °C (59 °F)
or below, use the starter knob/idle screw.
2. Completely close the throttle.
3. Start the engine by pushing the start switch.
If the engine fails to start when using the
start switch, release it, wait a few seconds,
and then try again.
Each starting attempt should be as short as
possible to preserve the battery. Do not
crank the engine more than 10 seconds on
any one attempt.
Recommended fuel
Premium unleaded gasoline
(Gasohol [E10] acceptable)
Fuel tank capacity
7.5 L (2.0 US gal, 1.7 Imp.gal)
Fuel reserve amount
2.1 L (0.55 US gal, 0.46 Imp.gal)
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