check engine YAMAHA WR 250F 2015 Owners Manual
Page 7 of 430
EAS2GB2005
SAFETY INFORMATION
THIS MACHINE IS DESIGNED STRICTLY FOR COMPETITION USE, ONLY ON A CLOSED 
COURSE. It is illegal for this machine to be operated on any public street, road, or highway. Off-road 
use on public lands may also be illegal. Please check local regulations before riding.
• THIS MACHINE IS TO BE OPERATED BY AN EXPERIENCED RIDER ONLY.
Do not attempt to operate this machine at maximum power until you are totally familiar with its char-
acteristics.
• THIS MACHINE IS DESIGNED TO BE RIDDEN BY THE OPERATOR ONLY.
Do not carry passengers on this machine.
• ALWAYS WEAR PROTECTIVE APPAREL.
When operating this machine, always wear an approved helmet with goggles or a face shield. Also 
wear heavy boots, gloves, and protective clothing. Always wear proper fitting clothing that will not 
be caught in any of the moving parts or controls of the machine.
• ALWAYS MAINTAIN YOUR MACHINE IN PROPER WORKING ORDER.
For safety and reliability, the machine must be properly maintained. Always perform the pre-oper-
ation checks indicated in this manual.
Correcting a mechanical problem before you ride may prevent an accident.
• GASOLINE IS HIGHLY FLAMMABLE.
Always turn off the engine while refueling. Take care to not spill any gasoline on the engine or ex-
haust system. Never refuel in the vicinity of an open flame, or while smoking.
• GASOLINE CAN CAUSE INJURY.
If you should swallow some gasoline, inhale excess gasoline vapors, or allow any gasoline to get 
into your eyes, contact a doctor immediately. If any gasoline spills onto your skin or clothing, imme-
diately wash skin areas with soap and water, and change your clothes.
• ONLY OPERATE THE MACHINE IN AN AREA WITH ADEQUATE VENTILATION.
Never start the engine or let it run for any length of time in an enclosed area. Exhaust fumes are 
poisonous. These fumes contain carbon monoxide, which by itself is odorless and colorless. Car-
bon monoxide is a dangerous gas which can cause unconsciousness or can be lethal.
• PARK THE MACHINE CAREFULLY; TURN OFF THE ENGINE.
Always turn off the engine if you are going to leave the machine. Do not park the machine on a slope 
or soft ground as it may fall over.
• THE ENGINE, EXHAUST PIPE AND MUFFLER WILL BE VERY HOT AFTER THE ENGINE HAS 
BEEN RUN.
Be careful not to touch them or to allow any clothing item to contact them during inspection or repair.
• PROPERLY SECURE THE MACHINE BEFORE TRANSPORTING IT.
For safety, drain the gasoline from the fuel tank before transporting the vehicle. 
Page 11 of 430
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TOCTOC
TABLE OF CONTENTS
GENERAL INFORMATION
SPECIFICATIONS
PERIODIC CHECKS AND ADJUST-
MENTS
TUNING
CHASSIS
ENGINE
COOLING SYSTEM
FUEL SYSTEM
ELECTRICAL SYSTEM
TROUBLESHOOTING 
Page 14 of 430
CONTROL FUNCTIONS................................................................................ 1-21
INDICATOR LIGHTS AND WARNING LIGHTS ....................................... 1-21
ENGINE STOP SWITCH .......................................................................... 1-21
START SWITCH....................................................................................... 1-21
CLUTCH LEVER...................................................................................... 1-21
SHIFT PEDAL .......................................................................................... 1-22
KICKSTARTER LEVER............................................................................ 1-22
THROTTLE GRIP ..................................................................................... 1-22
FRONT BRAKE LEVER ........................................................................... 1-22
REAR BRAKE PEDAL.............................................................................. 1-22
SIDESTAND ............................................................................................. 1-23
STARTER KNOB/IDLE ADJUSTING SCREW ......................................... 1-23
FUEL TANK CAP ..................................................................................... 1-23
MULTI-FUNCTION DISPLAY......................................................................... 1-24
DESCRIPTION ......................................................................................... 1-24
BASIC MODE ........................................................................................... 1-24
CHANGEOVER TO BASIC MODE/RACE MODE.................................... 1-25
RACE MODE ............................................................................................ 1-26
FUNCTION DIAGRAM ............................................................................. 1-30
STARTING AND BREAK-IN.......................................................................... 1-32
FUEL ........................................................................................................ 1-32
HANDLING NOTE .................................................................................... 1-32
AIR FILTER MAINTENANCE ................................................................... 1-32
STARTING A COLD ENGINE .................................................................. 1-32
STARTING A WARM ENGINE ................................................................. 1-33
BREAK-IN PROCEDURES ...................................................................... 1-34
MAINTENANCE AFTER BREAK-IN.............................................................. 1-35
MAJOR MAINTENANCE .......................................................................... 1-35
TORQUE-CHECK POINTS............................................................................ 1-36
MOTORCYCLE CARE AND STORAGE........................................................ 1-38
CARE........................................................................................................ 1-38
STORAGE ................................................................................................ 1-39 
Page 18 of 430
DESCRIPTION
1-4
EAS2GB2009
DESCRIPTION
TIP
Designs and specifications of the vehicle are subject to change without notice. Therefore, please 
note that the descriptions in this manual may be different from those for the vehicle you have pur-
chased.1. Clutch lever 12. Headlight
2. Multi-function display 13. Radiator
3. Front brake lever 14. Coolant drain bolt
4. Throttle grip 15. Rear brake pedal
5. Start switch 16. Air filter
6. Radiator cap 17. Drive chain
7. Fuel tank cap 18. Shift pedal
8. Engine stop switch 19. Oil level check window
9. Taillight 20. Starter knob/idle screw
10. Fuel tank 21. Front fork
11. Kickstarter lever
32 1
8
10
91112 1376
54
15 14 21 20 19 18 1716 
Page 23 of 430
IMPORTANT INFORMATION
1-9
EAS20180
IMPORTANT INFORMATION
EAS2GB2022PREPARATION FOR REMOVAL AND DIS-
ASSEMBLY
1. Before the jobs, completely remove mud, 
dust, and the like in order to prevent the en-
try of them into the inside during the jobs.
• Before cleaning with high-pressure water of 
washers, cover the following parts.
Air duct
Silencer exhaust port
Drain hole on the cylinder head (right side)
Hole under the water pump housing
2. Use proper special tools and equipment. 
See “SPECIAL TOOLS”.
3. During disassembly, check and measure the 
required parts, and make a record of them 
so that you may refer to the record when in-
stalling them. Moreover, arrange gears, cyl-
inders, pistons, and other parts for each 
section so as not to confuse or lose them.4. During disassembly, clean each of the parts, 
and store them in trays for each section.
5. Flammable. Keep servicing areas away 
from any source of fire.
6.  During servicing, take special care not to re-
ceive an injury or a burn on the engine, the 
exhaust pipe, the silencer, or the like.
7. If coolant is left adhered to the chassis, paint 
and plating will be damaged. Therefore, 
rinse it out with water in good time.
EWA
WARNING
Coolant is potentially harmful and should 
be handled with special care.
• If it enters your eyes, wash it away with wa-
ter enough and then get medical attention
• If it splashes on your skin or clothes, 
quickly wash it away with water and then 
with soapy water.
• If it is swallowed, immediately induce vom-
iting and get medical attention.
EAS2GB2023REPLACEMENT PARTS
Make sure that the parts and grease or oil to be 
used for repair of the vehicle, including periodic 
replacement parts, are new YAMAHA genuine 
parts and recommended parts.
Do not use any used parts, because these may 
not be genuine though they have similar ap-
pearances or because the quality may be 
changed by aging. 
Page 26 of 430
BASIC SERVICE INFORMATION
1-12
ECA
NOTICE
Handle electrical components with special 
care, and do not subject them to strong 
shocks.
ECA
NOTICE
Electrical components are very sensitive to 
and can be damaged by static electricity. 
Therefore, never touch the terminals and be 
sure to keep the contacts clean.
TIP
Push and hold the engine stop switch to turn off 
the multi-function display when resetting the 
ECU (Electronic Control Unit). Disconnect the 
starter motor lead of the starter relay, and then 
push the starter switch. Be sure to wait for five 
seconds or longer before pushing the start 
switch after the multi-function display goes off.Checking the electrical system
TIP
Before checking the electrical system, make 
sure that the battery voltage is at least 12 V.
ECA
NOTICE
Never insert the tester probes into the cou-
pler terminal slots. Always insert the probes 
from the opposite end “a” of the coupler, 
taking care not to loosen or damage the 
leads.
ECA
NOTICE
For waterproof couplers, never insert the 
tester probes directly into the coupler. 
When performing any checks using a water-
proof coupler, use the specified test har-
ness or a suitable commercially available 
test harness.
a 
Page 35 of 430
CONTROL FUNCTIONS
1-21
EAS2GB2031
CONTROL FUNCTIONS
EAS2GB2032INDICATOR LIGHTS AND WARNING 
LIGHTS
1. Engine trouble warning light “ ”
2. Fuel level warning light “ ”
Fuel level warning light “ ”
This warning light comes on when the fuel level 
drops below approximately 1.6 L (0.42 US gal, 
0.35  Imp.gal). When this occurs, refuel as soon 
as possible.
The electrical circuit of the warning light can be 
checked by pushing the start switch. The warn-
ing light should come on for a few seconds, and 
then go off.
If the warning light does not come on initially 
when the start switch is pushed, or if the warn-
ing light remains on, have a Yamaha dealer 
check the electrical circuit.
Engine trouble warning light “ ”
This warning light comes on or flashes if a prob-
lem is detected in the electrical circuit monitor-
ing the engine. If this occurs, have a Yamaha 
dealer check the vehicle.
The electrical circuit of the warning light can be 
checked by pushing the start switch. The warn-
ing light should come on for a few seconds, and 
then go off.
If the warning light does not come on initially 
when the start switch is pushed, or if the warn-
ing light remains on, have a Yamaha dealer 
check the electrical circuit.
EAS2GB2033ENGINE STOP SWITCH
The engine stop switch “1” is located on the left 
handlebar. Continue pushing the engine stop 
switch till the engine comes to a stop.
After the engine stops, the multi-function dis-
play will go off and the power supply to the ECU 
(Electronic Control Unit) will be cut off if the en-
gine stop switch is pushed and held.
TIP
The multi-function display will go off after one 
minute if the engine stop switch is not pushed.
EAS2GB2034START SWITCH
The start switch “1” is located on the right han-
dlebar. Push this switch to crank the engine 
with the starter.
EAS2GB2035CLUTCH LEVER
The clutch lever “1” is located on the left han-
dlebar. The clutch lever disengages or engag-
es the clutch.
Pull the clutch lever toward the handlebar to 
disengage the clutch, and release the lever to 
engage the clutch.
12 
Page 46 of 430
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 
Page 48 of 430
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. 
Page 49 of 430
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.