Yamaha XT500E Owner's Manual page 49

PERIODIC MAINTENANCE AND MINOR REPAIR
Inspection
The spark plug is an important
engine component and is easy to
1
inspect. The condition of the spark
plug can indicate the condition of the
2
engine.
The ideal color on the white insulator
3 around the center electrode is a
medium-to-light tan color for a motor-
cycle that is being ridden normally.
4
Do not attempt to diagnose such
problems yourself. Instead, take the
5
motorcycle to a Yamaha dealer. You
should periodically
6
inspect the spark plug because heat
and deposits will cause any spark
7
plug to slowly break down and erode.
If electrode erosion becomes exces-
8
sive, or if carbon and other deposits
are excessive, you should replace
the spark plug with the specified plug.
9
Specified spark plug:
DPR8EA-9 or
DPR9EA-9 (NGK)
1
1. Spark plug gap
Installation
1. Measure the electrode gap with
a wire thickness gauge and, if
necessary, adjust the gap to
remove and
specification.
Spark plug gap:
0.8 ~ 0.9 mm
2. Clean the gasket surface. Wipe
off any grime from the threads.
3. Install the spark plug and tighten
it to the specified torque.
Tightening torque:
Spark plug:
17.5 Nm (1.75 m0kg)
6-9
NOTE:
If a torque wrench is not available
when you are installing a spark plug,
a good estimate of the correct torque
is 1/4 to 1/2 turn past finger tight.
Have the spark plug tightened to the
specified torque as soon as possible.
4. Install the spark plug cap.