ENGINE
3-10
7. Measure:
●
Compression pressure
Out of specification
→
Refer to steps (c) and
(d).
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Set the main switch to “ON”.
b. With the throttle wide open, crank the engine
until the reading on the compression gauge
stabilizes.
NOTE:
●
Make use the battery is fully charged when tak-
ing measurements.
●
Make sure there is no compression leakage
from the connecting section of the compres-
sion gauge.
c. If the compression pressure is above the
maximum specification, check the cylinder
head, valve surfaces and piston crown for
carbon deposits.
Carbon deposits
→
Eliminate.
d. If the compression pressure is below the min-
imum specification, pour a teaspoonful of en-
gine oil into the spark plug bore and measure
again.
Refer to the following table.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
8. Install:
●
Spark plug
9. Install:
●
Ignition coil assembly
10.Connect:
●
Ignition coil assembly lead coupler
11.Install:
●
Fuel tank
Refer to “FUEL TANK” on page 7-1.
●
Air scoop (left/right)
●
Side cover (left/right)
●
Seat
Refer to “GENERAL CHASSIS” on page 4-1.
EAS20730
CHECKING THE ENGINE OIL LEVEL
1. Stand the vehicle on a level surface.
NOTE:
●
Place the vehicle on a suitable stand.
●
Make sure the vehicle is upright.
2. Start the engine, warm it up for several min-
utes, and then turn it off.
3. Check:
●
Engine oil level
The engine oil level should be between the
minimum level mark “a” and maximum level
mark “b”.
Below the minimum level mark
→
Add the
recommended engine oil to the proper level.
Compression pressure (Stan-
dard)
850 kPa (121 psi) (8.5 kg/cm
2
)
Compression pressure (Mini-
mum)
740 kPa (105 psi) (7.4 kg/cm
2
)
Compression pressure (Maxi-
mum)
950 kPa (135 psi) (9.5 kg/cm
2
)
Compression pressure (with oil applied into the
cylinder)
Reading
Diagnosis
Higher than without oil
Piston ring (s) wear or
damage
→
Repair.
1
Same as without oil
Piston, valves, cylinder
head gasket or pis-
ton possibly defec-
tive
→
Repair.
Spark plug
13 Nm (1.3 m•kg, 9.4 ft•lb)
T
R
.
.
b
a
Summary of Contents for WR250R
Page 1: ...SERVICE MANUAL WR250RX C 2008 32C 28197 10 WR250XX C LIT 11616 21 66 ...
Page 2: ......
Page 8: ......
Page 39: ...ELECTRICAL SPECIFICATIONS 2 14 Spare fuse 15 0 A Spare fuse 10 0 A Spare fuse 7 5 A ...
Page 49: ...LUBRICATION POINTS AND LUBRICANT TYPES 2 24 ...
Page 52: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 27 ...
Page 54: ...COOLING SYSTEM DIAGRAMS 2 29 EAS20420 COOLING SYSTEM DIAGRAMS 8 5 1 2 3 4 6 7 9 ...
Page 56: ...CABLE ROUTING 2 31 EAS20430 CABLE ROUTING ...
Page 58: ...CABLE ROUTING 2 33 ...
Page 60: ...CABLE ROUTING 2 35 ...
Page 62: ...CABLE ROUTING 2 37 ...
Page 64: ...Front rear brake hose 2 39 Front rear brake hose ...
Page 66: ...Throttle body 2 41 Throttle body ...
Page 68: ...Canister for California 2 43 Canister for California 5mm 0 20 in 4 5 ...
Page 70: ...Canister for California 2 45 ...
Page 106: ...ELECTRICAL SYSTEM 3 34 a b a b ...
Page 107: ...ELECTRICAL SYSTEM 3 35 ...
Page 108: ...ELECTRICAL SYSTEM 3 36 ...
Page 116: ...FRONT WHEEL 4 6 1 ...
Page 229: ...GENERATOR AND STARTER CLUTCH 5 55 1 2 ...
Page 244: ...TRANSMISSION 5 70 ...
Page 254: ...WATER PUMP 6 9 ...
Page 258: ...FUEL TANK 7 3 1 ...
Page 263: ...THROTTLE BODIES 7 8 ...
Page 264: ...AIR INDUCTION SYSTEM 7 9 EAS27040 AIR INDUCTION SYSTEM 2 1 3 4 ...
Page 271: ......
Page 272: ...IGNITION SYSTEM 8 1 EAS27090 IGNITION SYSTEM EAS27100 CIRCUIT DIAGRAM ...
Page 276: ...ELECTRIC STARTING SYSTEM 8 5 EAS27160 ELECTRIC STARTING SYSTEM EAS27170 CIRCUIT DIAGRAM ...
Page 282: ...CHARGING SYSTEM 8 11 EAS27200 CHARGING SYSTEM EAS27210 CIRCUIT DIAGRAM ...
Page 283: ...CHARGING SYSTEM 8 12 1 AC magneto 2 Rectifier regulator 4 Battery 5 Main fuse ...
Page 285: ...CHARGING SYSTEM 8 14 ...
Page 286: ...LIGHTING SYSTEM 8 15 EAS27240 LIGHTING SYSTEM EAS27250 CIRCUIT DIAGRAM ...
Page 289: ...LIGHTING SYSTEM 8 18 ...
Page 290: ...SIGNALING SYSTEM 8 19 EAS27270 SIGNALING SYSTEM EAS27280 CIRCUIT DIAGRAM ...
Page 295: ...SIGNALING SYSTEM 8 24 ...
Page 296: ...COOLING SYSTEM 8 25 EAS27300 COOLING SYSTEM EAS27310 CIRCUIT DIAGRAM ...
Page 299: ...COOLING SYSTEM 8 28 ...
Page 300: ...FUEL INJECTION SYSTEM 8 29 EAS27330 FUEL INJECTION SYSTEM EAS27340 CIRCUIT DIAGRAM ...
Page 326: ...FUEL PUMP SYSTEM 8 55 EAS27580 FUEL PUMP SYSTEM EAS27590 CIRCUIT DIAGRAM ...
Page 329: ...FUEL PUMP SYSTEM 8 58 ...
Page 332: ...ELECTRICAL COMPONENTS 8 61 2 3 4 9 5 10 14 13 1 6 7 11 12 15 8 ...
Page 334: ...ELECTRICAL COMPONENTS 8 63 EAS27980 CHECKING THE SWITCHES 7 9 8 11 10 4 2 3 5 6 1 ...
Page 358: ...TROUBLESHOOTING 9 5 ...
Page 360: ......
Page 361: ......
Page 362: ...YAMAHA MOTOR CO LTD 2500 SHINGAI IWATA SHIZUOKA JAPAN ...