2015 YAMAHA WR 250F engine

CONTROL FUNCTIONS
1-23
EAS2GB2041SIDESTAND
This sidestand “1” is used to support only the
machine when standing or transporting it.
EWA
WARNING
• Never apply additional force to the sides-
tand.
• Hold up the sidestand before starting out.
EAS2GB2042STARTER KNOB/IDLE ADJUSTING SCREW
Starting a cold engine requires a larger amount
of intake air, which is supplied by the starter
knob/idle screw “1”.
Pulling the knob toward “a” turns ON the start-
er, resulting in a larger amount of intake air.
Pushing the knob toward “b” turns OFF the
starter.
EWA
WARNING
While handling the starter knob/idle screw,
take care not to burn yourself on exhaust
pipes.
EAS2GB2043
FUEL TANK CAP
Fuel tank cap “1” is located under the fuel tank
cap cover “2”.
Remove the fuel tank cap cover to open the fuel
tank cap.
TIP
• To remove the fuel tank cap cover, insert fin-
gers under part “a”, and then use both hands
to lift it up towards the rear of the vehicle.
• Install the fuel tank cap cover after placing the
bands “3” all the way in under the seat.
1
ab1
1
23
a
2

STARTING AND BREAK-IN
1-32
EAS2GB2050
STARTING AND BREAK-IN
EAS2GB2051FUEL
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 (For USA and Canada)
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.
EAS2GB2052HANDLING NOTEEWA
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
• Unlike a two-stroke engine, this engine
cannot be kick started when the throttle is
open because the kickstarter may kick
back. Also, 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.
EAS2GB2053AIR FILTER MAINTENANCE
According to “CLEANING THE AIR FILTER
ELEMENT” section in the CHAPTER 3, apply
the foam-air-filter oil or its equivalent to the ele-
ment. (Excess oil in the element may adversely
affect engine starting.)
EAS2GB2054STARTING A COLD ENGINEECA
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. If the engine does not start
with the starter motor, try using the kickstart-
er. Recommended fuel
Premium unleaded gasoline
Fuel tank capacity
7.5 L (1.98 US gal, 1.65 lmp.gal)
Fuel reserve amount
1.6 L (0.42 US gal, 0.35 lmp.gal)
1

STARTING AND BREAK-IN
1-33
ECA
NOTICE
If the starter motor will not turn when the
start switch is pushed, stop pushing it im-
mediately in order to avoid placing extra
load on the starter motor, and start the en-
gine by using the kickstarter.
TIP
If the engine fails to start, push the engine stop
switch and give the kickstarter 10 to 20 slow
kicks at full throttle in order to clear the engine
of the rich air-fuel mixture retained in it.
4. When the engine starts running, warm this
up one or two minutes at a steady speed (of
3000 to 5000 r/min), and then return the
starter knob/idle screw to its original posi-
tion.
EWA
WARNING
Since exhaust gas contains harmful ingre-
dients, do not start or warm it up at an ill-
ventilated place or a closed narrow place.
5. To stop the engine, push the engine stop
switch “1”.
TIP
Continue pushing the engine stop switch till the
engine comes to a full stop.Starting with the kickstarter
When using the kickstarter to start the engine,
follow the procedures as described below.
1. Fold out the kickstarter lever, push it down
lightly with your foot until resistance is felt.
2. With the throttle fully closed,push the kick-
starter down lightly until the gears engage,
and then push it down smoothly but forceful-
ly.
EWA
WARNING
Do not open the throttle while kicking the
kickstarter lever. Otherwise, the kickstarter
lever may kick back.
TIP
If the engine fails to start, push the engine stop
switch and give the kickstarter 10 to 20 slow
kicks at full throttle in order to clear the engine
of the rich air-fuel mixture retained in it.
EAS2GB2055STARTING A WARM ENGINE
Follow the same procedure as for starting a
cold engine with the exception that the starter is
not required when the engine is warm.
TIP
If it fails to start, fully open the throttle grip and
give 10 to 20 slow kicks to clear the engine of
the rich air-fuel mixture retained in it.

STARTING AND BREAK-IN
1-34
EAS2GB2056BREAK-IN PROCEDURES
A break-in is important so that rotating portion,
sliding surfaces, and mounted areas may fit
one another, and that the rider may become ac-
customed to the machine.
ECA
NOTICE
Before running, do maintenance on the air
filter element.
Refer to “CLEANING THE AIR FILTER ELE-
MENT” on page 3-14.
1. After warming up the engine, drive it for
about 20 minutes at a throttle opening of 1/2
or less.
2. Make a pit stop, and check mounted areas
for looseness, oil leaks, or other problems.
3. Then, drive it for about 40 minutes at a throt-
tle opening of 3/4 or less.
4. Make a pit stop again, and thoroughly check
mounted areas for looseness, oil leaks, or
other problems. Thorough checks and ad-
justments are required in particular for
stretch of cables, free play of the brake,
stretch of the drive chain, looseness of the
spoke, and so on.
ECA
NOTICE
After a break-in or after each race, always
check the points shown in “TORQUE-
CHECK POINTS” for tightening torques and
retighten them. (Refer to “TORQUE-CHECK
POINTS” on page 1-36.)
Also when the following parts are replaced,
a break-in is required.
• Cylinder and Crankshaft: A break-in is re-
quired for about an hour.
• Piston, Piston ring, Valve, Camshaft, and
Gear: A break-in is required for about 30
minutes at a throttle opening of 1/2 or less.
Observe the condition of the engine careful-
ly during a break-in.
For checkpoints for a break-in, see “MAIN-
TENANCE AFTER BREAK-IN”. If any prob-
lem is found, immediately stop the engine
and make a checkup.

MAINTENANCE AFTER BREAK-IN
1-35
EAS2GB2057
MAINTENANCE AFTER BREAK-IN
After a break-in, perform careful maintenance
to get ready for the next practice or race.
Refer to “PRE-OPERATION INSPECTION
AND MAINTENANCE” on page 3-9.
EAS2GB2058MAJOR MAINTENANCE
1. For the engine
• Leaks around the engine
Check for pressure leaks from the cylinder
head or the cylinder, oil leaks from the
crankcase or the case cover, leaks from the
coolant system, and other leaks.
• Check that the valve, the cylinder head, the
cylinder, the piston, and the piston ring fit
one another, and that contact between the
valve and the cylinder head, and that be-
tween the cylinder and the piston are cor-
rect.
• Engine oil change
Drain the oil, and check for dirt and foreign
materials such as metal chips. (If any foreign
material is mixed, disassemble and check
the crankcase.)
Pour the specified amount of the recom-
mended oil.
• AC magneto
Check for looseness in mounted areas of
the rotor and the stator.
Check that the connector is not being dis-
connected.
• Silencer
Check the main body and stay for cracks.
Check for leaks.
• Mounting bolts and nuts
Check for looseness in mounted areas of
parts, as well as engine mounting bolts and
engine brackets.
2. For the chassis
• Check welds and mounted areas of the
frame, the swingarm, the link, the bracket,
and so on, for looseness and cracks.
• Wheel (s)
Check the wheel for runout. Check the
spoke for looseness.
• Brake(s)
Check the brake disc mounting bolt for
looseness.
Check that the reservoir contains the speci-
fied amount of brake fluid. Check for leaks.• Cable
Grease and adjust cables.
•Drive chain
Lubricate the drive chain and adjust its ten-
sion.
• Fuel tank
Clean the inside of the fuel tank. Check for
leaks.
• Suspension
Check for oil leaks in the front fork or the rear
shock absorber. Check that the mounted
conditions are good.
• Sprocket
Check for looseness in the sprocket mount-
ed on the rear wheel.
• Mounting bolts and nuts
Check mounted areas for looseness.
ECA
NOTICE
After a break-in or before each race, always
check the points shown in “TORQUE-
CHECK POINTS” for tightening torques and
retighten them. (Refer to “TORQUE-CHECK
POINTS” on page 1-36.)
• Greasing and oiling
Always grease or oil the specified points.

TORQUE-CHECK POINTS
1-36
EAS2GB2059
TORQUE-CHECK POINTS
Frame construction Frame to rear frame
Frame to engine protector
Combined seat and fuel tank Fuel tank to frame
Engine mounting Frame to engine
Engine bracket to engine
Engine bracket to frame
Seat Seat to frame
Steering Steering stem to handlebar Steering stem to frame
Steering stem to upper bracket
Upper bracket to handlebar
Suspension Front Steering stem to front fork Front fork to upper bracket
Front fork to lower bracket
Rear Link Assembly of links
Link to frame
Link to rear shock absorber
Link to swingarm
Mounting of rear shock absorber Rear shock absorber and frame
Mounting of swingarm Tightening of pivot shaft
Wheel (s) Mounting of wheel Front Tightening of wheel axle
Tightening of axle holder
Tightening of spoke nipple
Rear Tightening of wheel axle
Wheel to rear wheel sprocket
Tightening of spoke nipple
Brake(s) Front Brake caliper to front fork
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to handle-
bar
Tightening of bleed screw
Tightening of brake hose holder
Rear Brake pedal to frame
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to frame
Tightening of bleed screw
Tightening of brake hose holder
Shift pedal Shift pedal to shift shaft

MOTORCYCLE CARE AND STORAGE
1-38
EAS2GB2060
MOTORCYCLE CARE AND STOR-
AGE
EAS2GB2061CARE
While the open design of a motorcycle reveals
the attractiveness of the technology, it also
makes it more vulnerable. Rust and corrosion
can develop even if high-quality components
are used. A rusty exhaust pipe may go unno-
ticed on a car, however, it detracts from the
overall appearance of a motorcycle. Frequent
and proper care does not only comply with the
terms of the warranty, but it will also keep your
motorcycle looking good, extend its life and op-
timize its performance.
Before cleaning
1. Cover the muffler outlet with a plastic bag af-
ter the engine has cooled down.
2. Make sure that all caps and covers as well
as all electrical couplers and connectors, in-
cluding the spark plug cap, are tightly in-
stalled.
3. Remove extremely stubborn dirt, like oil
burnt onto the crankcase, with a degreasing
agent and a brush, but never apply such
products onto seals, gaskets, sprockets, the
drive chain and wheel axles. Always rinse
the dirt and degreaser off with water.
Cleaning
ECA
NOTICE
• Avoid using strong acidic wheel cleaners,
especially on spoked wheels. If such prod-
ucts are used on hard-to-remove dirt, do
not leave the cleaner on the affected area
any longer than instructed. Also, thor-
oughly rinse the area off with water, imme-
diately dry it, and then apply a corrosion
protection spray.
• Improper cleaning can damage plastic
parts (such as cowlings, panels, wind-
shields, headlight lenses, meter lenses,
etc.) and the mufflers. Use only a soft,
clean cloth or sponge with water to clean
plastic. However, if the plastic parts can-
not be thoroughly cleaned with water, di-
luted mild detergent with water may be
used. Be sure to rinse off any detergent
residue using plenty of water, as it is
harmful to plastic parts.• Do not use any harsh chemical products
on plastic parts. Be sure to avoid using
cloths or sponges which have been in con-
tact with strong or abrasive cleaning prod-
ucts, solvent or thinner, fuel (gasoline),
rust removers or inhibitors, brake fluid,
antifreeze or electrolyte.
• Do not use high-pressure washers or
steam-jet cleaners since they cause water
seepage and deterioration in the following
areas: seals (of wheel and swingarm bear-
ings, fork and brakes), electric compo-
nents (couplers, connectors, instruments,
switches and lights), breather hoses and
vents.
• For motorcycles equipped with a wind-
shield: Do not use strong cleaners or hard
sponges as they will cause dulling or
scratching. Some cleaning compounds for
plastic may leave scratches on the wind-
shield. Test the product on a small hidden
part of the windshield to make sure that it
does not leave any marks. If the wind-
shield is scratched, use a quality plastic
polishing compound after washing.
After normal use
Remove dirt with warm water, a mild detergent,
and a soft, clean sponge, and then rinse thor-
oughly with clean water. Use a toothbrush or
bottlebrush for hard-to-reach areas. Stubborn
dirt and insects will come off more easily if the
area is covered with a wet cloth for a few min-
utes before cleaning.
After riding in the rain, near the sea or on salt-
sprayed roads
Since sea salt or salt sprayed on roads during
winter are extremely corrosive in combination
with water, carry out the following steps after
each ride in the rain, near the sea or on salt-
sprayed roads.
TIP
Salt sprayed on roads in the winter may remain
well into spring.
1. Clean the motorcycle with cold water and a
mild detergent, after the engine has cooled
down.
NOTICE: Do not use warm water since it
increases the corrosive action of the salt.

MOTORCYCLE CARE AND STORAGE
1-39
2. Apply a corrosion protection spray on all
metal, including chrome- and nickel-plated,
surfaces to prevent corrosion.
After cleaning
1. Dry the motorcycle with a chamois or an ab-
sorbing cloth.
2. Immediately dry the drive chain and lubri-
cate it to prevent it from rusting.
3. Use a chrome polish to shine chrome, alumi-
num and stainless- steel parts, including the
exhaust system. (Even the thermally in-
duced discoloring of stainless- steel exhaust
systems can be removed through polishing.)
4. To prevent corrosion, it is recommended to
apply a corrosion protection spray on all
metal, including chrome- and nickel-plated,
surfaces.
5. Use spray oil as a universal cleaner to re-
move any remaining dirt.
6. Touch up minor paint damage caused by
stones, etc.
7. Wax all painted surfaces.
8. Let the motorcycle dry completely before
storing or covering it.
EWA
WARNING
Contaminants on the brakes or tires can
cause loss of control.
• Make sure that there is no oil or wax on the
brakes or tires.
• If necessary, clean the brake discs and
brake linings with a regular brake disc
cleaner or acetone, and wash the tires with
warm water and a mild detergent. Before
riding at higher speeds, test the motorcy-
cle’s braking performance and cornering
behavior.
ECA
NOTICE
• Apply spray oil and wax sparingly and
make sure to wipe off any excess.
• Never apply oil or wax to any rubber and
plastic parts, but treat them with a suitable
care product.
• Avoid using abrasive polishing com-
pounds as they will wear away the paint.
TIP
• Consult a Yamaha dealer for advice on what
products to use.
• Washing, rainy weather or humid climates
can cause the headlight lens to fog. Turning
the headlight on for a short period of time will
help remove the moisture from the lens.
EAS2GB2062STORAGE
Short-term
Always store your motorcycle in a cool, dry
place and, if necessary, protect it against dust
with a porous cover. Be sure the engine and the
exhaust system are cool before covering the
motorcycle.
ECA
NOTICE
• Storing the motorcycle in a poorly ventilat-
ed room or covering it with a tarp, while it
is still wet, will allow water and humidity to
seep in and cause rust.
• To prevent corrosion, avoid damp cellars,
stables (because of the presence of am-
monia) and areas where strong chemicals
are stored.
Long-term
Before storing your motorcycle for several
months:
1. Follow all the instructions in the “Care” sec-
tion of this chapter.
2. Fill up the fuel tank and add fuel stabilizer (if
available) to prevent the fuel tank from rust-
ing and the fuel from deteriorating.
3. Perform the following steps to protect the
cylinder, piston rings, etc. from corrosion.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
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 sparking during the
next step.)
d. Turn the engine over several times with the
starter. (This will coat the cylinder wall with
oil.)