Yamaha WR250FM Bicycle User Manual


 
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INSP
ADJ
ELECTRICAL/SPARK PLUG INSPECTION/
IGNITION TIMING CHECK
EC370000
ELECTRICAL
EC371001
SPARK PLUG INSPECTION
1. Remove:
Spark plug
2. Inspect:
Electrode 1
Wear/damage Replace.
Insulator color 2
Normal condition is a medium to light tan
color.
Distinctly different color Check the
engine condition.
N
OTE:
When the engine runs for many hours at low
speeds, the spark plug insulator will become
sooty, even if the engine and carburetor are in
good operating condition.
3. Measure:
Plug gap a
Use a wire gauge or thickness gauge.
Out of specification Regap.
4. Clean the plug with a spark plug cleaner if
necessary.
Spark plug gap:
0.7 ~ 0.8 mm (0.028 ~ 0.031 in)
5. Tighten:
Spark plug
N
OTE:
Before installing a spark plug, clean the gas-
ket surface and plug surface.
Finger-tighten a the spark plug before torqu-
ing to specification b.
T
R
.
.
13 Nm (1.3 m · kg, 9.4 ft · lb)
IGNITION TIMING CHECK
1. Remove:
Timing mark accessing screw 1