ELECTRICAL/SPARK PLUG INSPECTION/ IGNITION TIMING CHECK

EC370000

INSP

ADJ

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.

NOTE:

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.

Spark plug gap:

0.7~ 0.8 mm (0.028 ~ 0.031 in)

4.Clean the plug with a spark plug cleaner if necessary.

5.Tighten:

• Spark plug

T.

R.

13 Nm (1.3 m · kg, 9.4 ft · lb)

NOTE:

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.

IGNITION TIMING CHECK

1.Remove:

• Timing mark accessing screw 1

3 - 47

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Yamaha WR250FM Electrical, Spark Plug Inspection, Spark plug gap ~ 0.8 mm 0.028 ~ 0.031, Ignition Timing Check