CYLINDER HEAD
5-15
EAS24130
REMOVING THE CYLINDER HEAD
1. Remove:
●
Cylinder head bolts “1” (M6
×
60)
●
Cylinder head bolts “2” (M10
×
154)
●
Cylinder head bolts “3” (M10
×
140)
NOTE:
Gradually loosen bolts “a” to “f” in this sequence
in several times.
EAS24160
CHECKING THE CYLINDER HEAD
1. Eliminate:
●
Combustion chamber carbon deposits
(with a rounded scraper)
NOTE:
Do not use a sharp instrument to avoid damag-
ing or scratching:
●
Spark plug bore threads
●
Valve seats
2. Check:
●
Cylinder head
Damage/scratches
→
Replace.
●
Cylinder head water jacket
Mineral deposits/rust
→
Eliminate.
3. Measure:
●
Cylinder head warpage
Out of specification
→
Resurface the cylinder
head.
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a. Place a straightedge “1” and a thickness
gauge “2” across the cylinder head.
b. Measure the warpage.
c. If the limit is exceeded, resurface the cylinder
head as follows.
d. Place a 400
–
600 grit wet sandpaper on the
surface plate and resurface the cylinder head
using a figure-eight sanding pattern.
NOTE:
To ensure an even surface, turn the cylinder
head several times.
e. After resurfacing, out of specification
→
Re-
place the cylinder head.
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EAS24230
INSTALLING THE CYLINDER HEAD
1. Install:
●
Cylinder head gasket “1”
●
Dowel pins “2”
Cylinder head warpage
0.05 mm (0.002 in)
c
f
d
e
b
a
3
3
1
2
2
1
New
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 ...