2015 YAMAHA WR 250F Owners Manual

BASIC SERVICE INFORMATION
1-11
EAS2GB2028
BASIC SERVICE INFORMATION
EAS2GB2029ELECTRICAL SYSTEM
Electrical parts handling
ECA
NOTICE
Never disconnect a battery lead while the
engine is running; otherwise, the electrical
components could be damaged.
ECA
NOTICE
When disconnecting the battery leads from
the battery, be sure to disconnect the nega-
tive battery lead first, then the positive bat-
tery lead. If the positive battery lead is
disconnected first and a tool or similar item
contacts the vehicle, a spark could be gen-
erated, which is extremely dangerous.
TIP
If a battery lead is difficult to disconnect due to
rust on the battery terminal, remove the rust us-
ing hot water.
ECA
NOTICE
Be sure to connect the battery leads to the
correct battery terminals. Reversing the
battery lead connections could damage the
electrical components.
ECA
NOTICE
When connecting the battery leads to the
battery, be sure to connect the positive bat-
tery lead first, then the negative battery
lead. If the negative battery lead is connect-
ed first and a tool or similar item contacts
the vehicle while the positive battery lead is
being connected, a spark could be generat-
ed, which is extremely dangerous.
ECA
NOTICE
Make sure that the multi-function display
goes off after pushing and holding the en-
gine stop switch before disconnecting or
connecting any electrical components.

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

BASIC SERVICE INFORMATION
1-13
Checking the connections
Check the leads, couplers, and connectors for
stains, rust, moisture, etc.
1. Disconnect:
• Lead
• Coupler
• Connector
ECA
NOTICE
• When disconnecting a coupler, release the
coupler lock, hold both sections of the
coupler, and then disconnect the coupler.
• There are many types of coupler locks;
therefore, be sure to check the type of cou-
pler lock before disconnecting the cou-
pler.
ECA
NOTICE
When disconnecting a connector, do not
pull the leads. Hold both sections of the
connector, and then disconnect the con-
nector.2. Check:
• Lead
• Coupler
• Connector
Moisture  Dry with compressed air.
Rust/stains  Connect and disconnect sev-
eral times.
3. Check:
• All connections
Loose connection  Connect properly.
TIP
• If the pin “1” on the terminal is flattened, bend
it up.
• After disassembling or assembling a coupler,
pull on the leads to make sure that they are in-
stalled securely.
1

BASIC SERVICE INFORMATION
1-14
4. Connect:
• Lead
• Coupler
• Connector
TIP
• When connecting a coupler or connector,
make sure that both terminals are connected
securely.
• Make sure all connections are tight.
5. Check:
• No continuity
TIP
• If there is no continuity, clean the terminals.
• When checking the wire harness, perform
steps (1) to (4).
• As a quick remedy, use a contact revitalizer
available at most part stores.Pocket tester
90890-03112
Analog pocket tester
YU-03112-C

SPECIAL TOOLS
1-15
EAS2GB2030
SPECIAL TOOLS
The following special tools are required for accurate and complete adjustment and assembly. Using
the correct special tool will help prevent damage caused by the use of improper tools or improvised
techniques. The shape and tool number used for the special tool differ by country, so two types are
provided. Refer to the list provided to avoid errors when placing an order.
TIP
• For U.S.A. and Canada, use tool number starting with “YM-”, “YU-”, or “ACC-”.
• For others, use tool number starting with “90890-”.
Tool name/Part number How to use Illustration
Dial gauge & stand set
90890-01252
Dial gauge set
YU-03097-BThis tool is used to check
parts for runout or bend.
Crankshaft installer pot
90890-01274
Installing pot
YU-90058This tool is used to install the
crankshaft.
Crankshaft installer bolt
90890-01275
Bolt
YU-90060This tool is used to install the
crankshaft.
Adapter (M12)
90890-01278
Adapter #3
YU-90063This tool is used to install the
crankshaft.
Piston pin puller set
90890-01304
Piston pin puller
YU-01304This tool is used to remove
the piston pin.

SPECIAL TOOLS
1-16
Radiator cap tester
90890-01325
Mityvac cooling system tester
kit
YU-24460-AThis tool is used to check the
radiator and the radiator cap.
Radiator cap tester adapter
90890-01352
Pressure tester adapter
YU-33984This tool is used to check the
radiator and the radiator cap.
Steering nut wrench
90890-01403
Exhaust flange nut wrench
YU-A9472This tool is used to remove or
tighten the steering nut.
Cap bolt wrench
90890-01500
Cap bolt wrench
YM-01500This tool is used to remove or
tighten the base valve.
Cap bolt ring wrench
90890-01501
Cap bolt ring wrench
YM-01501This tool is used to loosen or
tighten the damper assem-
bly.
Fork seal driver
90890-01502
Fork seal driver (48)
YM-A0948This tool is used to install the
oil seal of the front fork.
Spoke nipple wrench (6–7)
90890-01521
Spoke nipple wrench (6–7)
YM-01521This tool is used to tighten the
spoke. Tool name/Part number How to use Illustration

SPECIAL TOOLS
1-17
Pocket tester
90890-03112
Analog pocket tester
YU-03112-CThis tool is used to measure
the voltage, current, and re-
sistance of electrical compo-
nents.
Timing light
90890-03141
Timing light
YU-03141This tool is used to measure
the ignition timing.
Pressure gauge
90890-03153
Pressure gauge
YU-03153This tool is used to measure
the fuel pressure.
Fuel pressure adapter
90890-03186
Fuel pressure adapter
YM-03186This tool is used to mount the
pressure gauge.
Test harness S– pressure
sensor (3P)
90890-03207
Test harness S– pressure
sensor (3P)
YU-03207This tool is used to check the
throttle position sensor input
voltage.
Test harness– lean angle
sensor (6P)
90890-03209
Test harness– lean angle
sensor (6P)This tool is used to check the
lean angle sensor output volt-
age.
FI diagnostic tool sub–lead
90890-03212
FI diagnostic tool sub–lead
YU-03212This tool is used to connect
the Yamaha diagnostic tool
to a battery.
Test harness– speed sensor
5TJ (3P)
90890-03228
Test harness– speed sensor
5TJ (3P)
YU-03228This tool is used to check the
speed sensor output voltage.
Yamaha diagnostic tool
90890-03231
Yamaha diagnostic tool (US)
90890-03234This tool is used to check er-
ror codes or carry out self-di-
agnosis. Tool name/Part number How to use Illustration

SPECIAL TOOLS
1-18
Valve spring compressor
90890-04019
Valve spring compressor
YM-04019This tool is used to discon-
nect or connect the valve and
the valve spring.
Spacer (crankshaft installer)
90890-04081
Pot spacer
YM-91044This tool is used to install the
crankshaft.
Universal clutch holder
90890-04086
Universal clutch holder
YM-91042This tool is used to hold the
clutch when removing or in-
stalling the clutch boss secur-
ing nut.
Valve guide remover (ø5)
90890-04097
Valve guide remover (5.0
mm)
YM-04097This tool is used to replace
the valve guide.
Valve guide installer (ø5)
90890-04098
Valve guide installer (5.0
mm)
YM-04098This tool is used to replace
the valve guide.
Valve guide reamer (ø5)
90890-04099
Valve guide reamer (5.0 mm)
YM-04099This tool is used to replace
the valve guide. Tool name/Part number How to use Illustration
YM-04019
YM-91044