ENGINE
3-7
EAS29170
ADJUSTING THE SPEED LIMITER
The speed limiter keeps the carburetor throttle
from becoming fully-opened even when the
throttle lever is applied to the maximum posi-
tion. Screwing in the adjusting screw stops the
engine speed from increasing.
1. Measure:
• Speed limiter length “a”
Out of specification
→
Adjust.
2. Adjust:
• Speed limiter length
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Loosen the locknut “1”.
b. Turn the adjusting screw “2” in or out until
the specified speed limiter length is
obtained.
c. Tighten the locknut.
WARNING
EWA14880
• Particularly for a beginner rider, the speed
limiter should be screwed in completely.
Screw it out little by little as their riding
technique improves. Never remove the
speed limiter for a beginning rider.
• For proper throttle lever operation do not
turn out the adjusting screw more than 12
mm (0.47 in). Also, always adjust the
throttle cable free play to 2.0–4.0 mm
(0.08–0.16 in).
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS20690
CHECKING THE SPARK PLUG
1. Disconnect:
• Spark plug cap
2. Remove:
• Spark plug
ECA13330
Before removing the spark plug, blow away
any dirt accumulated in the spark plug well
with compressed air to prevent it from fall-
ing into the cylinder.
3. Check:
• Spark plug type
Incorrect
→
Change.
4. Check:
• Electrode “1”
Damage/wear
→
Replace the spark plug.
• Insulator “2”
Abnormal color
→
Replace the spark
plug.
Normal color is medium-to-light tan.
5. Clean:
• Spark plug
(with a spark plug cleaner or wire brush)
6. Measure:
• Spark plug gap “a”
(with a wire thickness gauge)
Out of specification
→
Regap.
Speed limiter length
Less than 12 mm (0.47 in)
Direction “b”
Speed limiter length is
decreased.
Direction “c”
Speed limiter length is
increased.
Manufacturer/model
NGK/DR7EA
Spark plug gap
0.6–0.7 mm (0.024–0.028 in)
Summary of Contents for 2009 YFM25RY
Page 1: ...SERVICE MANUAL YFM25RY YFM25RSEY YFM25RSE2Y 4D3 28197 11 LIT 11616 22 09 2009 ...
Page 8: ......
Page 39: ...LUBRICATION POINTS AND LUBRICANT TYPES 2 20 ...
Page 42: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 23 EAS20410 LUBRICATION DIAGRAMS ...
Page 44: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 25 ...
Page 46: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 27 ...
Page 47: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 28 1 Oil cooler 2 Oil hose 1 3 Oil hose 2 ...
Page 48: ...CABLE ROUTING 2 29 EAS20430 CABLE ROUTING ...
Page 50: ...CABLE ROUTING 2 31 ...
Page 52: ...CABLE ROUTING 2 33 ...
Page 54: ...CABLE ROUTING 2 35 ...
Page 56: ...CABLE ROUTING 2 37 ...
Page 58: ...CABLE ROUTING 2 39 ...
Page 60: ...CABLE ROUTING 2 41 ...
Page 62: ...CABLE ROUTING 2 43 ...
Page 65: ......
Page 143: ...HANDLEBAR 4 42 Throttle cable free play 2 0 4 0 mm 0 08 0 16 in ...
Page 162: ...CHAIN DRIVE 4 61 ...
Page 165: ......
Page 240: ...CARBURETOR 6 9 ...
Page 242: ...IGNITION SYSTEM 7 1 EAS27090 IGNITION SYSTEM EAS27100 CIRCUIT DIAGRAM ...
Page 246: ...ELECTRIC STARTING SYSTEM 7 5 EAS27160 ELECTRIC STARTING SYSTEM EAS27170 CIRCUIT DIAGRAM ...
Page 252: ...CHARGING SYSTEM 7 11 EAS27200 CHARGING SYSTEM EAS27210 CIRCUIT DIAGRAM ...
Page 255: ...CHARGING SYSTEM 7 14 ...
Page 256: ...LIGHTING SYSTEM 7 15 EAS27240 LIGHTING SYSTEM EAS27250 CIRCUIT DIAGRAM ...
Page 260: ...SIGNALING SYSTEM 7 19 EAS27270 SIGNALING SYSTEM EAS27280 CIRCUIT DIAGRAM ...
Page 264: ...CARBURETOR HEATING SYSTEM 7 23 EAS27490 CARBURETOR HEATING SYSTEM EAS27500 CIRCUIT DIAGRAM ...
Page 267: ...CARBURETOR HEATING SYSTEM 7 26 ...
Page 268: ...ELECTRICAL COMPONENTS 7 27 EAS27972 ELECTRICAL COMPONENTS ...
Page 270: ...ELECTRICAL COMPONENTS 7 29 EAS27980 CHECKING THE SWITCHES ...
Page 284: ...ELECTRICAL COMPONENTS 7 43 ...
Page 291: ......
Page 292: ...YAMAHA MOTOR CO LTD 2500 SHINGAI IWATA SHIZUOKA JAPAN ...
Page 293: ...WIRING DIAGRAM YFM25RY YFM25RSEY YFM25RSE2Y ...