Ignition Lead - Stihl 009 User Manual

STIHL 009, 010, 011
Checking electrode gap
with feeler gauge
Never use a steel wire brush for
cleaning a sooted or carbonized spark
plug. Always use a brass wire brush
for this purpose and then blow out the
plug with compressed air. If the spark
plug is smeared with oil, wash the
insulator nose with a grease solvent
and blow out with compressed air.
As the electrode gap becomes wider
as a result of normal erosion the gap
must be checked with a feeler gauge
at regular intervals and reset as
necessary. The specified gap is
0.5 mm and can be restored by
bending the ground electrode. How-
ever, always fit a new spark plug if the
electrodes are badly eroded.
Accurate checking of the spark plug
is possible only with a special spark
plug tester. A provisional check can
be carried out by fitting the clean
spark plug in the ignition lead terminal
and holding it against ground. There
should be a powerful sparkover at the
electrodes when the engine is cranked
Resetting electrode gap with Bosch
spark plug gauge
by pulling the rewind starter.
If there is no sparkover although the
spark plug is in good condition, first
check the lead connections. Chafed
insulation on the ignition or ground
leads will cause a short-circuit to
ground. If this is the case the engine
will either not start or only run errati-
cally.
Before refitting the spark plug in the
cylinder, clean the spark plug seat and the ignition lead from the wood screw
make sure the sealing ring is in good
condition. Tighten down the spark
plug to a torque of 25 Nm (2.5 kpm).
4.4.2

Ignition Lead

Pulling out leg spring
The ignition lead feeds the high-
tension pulse generated in the arma-
ture to the spark plug. If its insulation
is brittle or damaged in any way a
sparkover to ground can occur and
thus interrupt the ignition process.
The ignition lead must be renewed in
such a case.
To remove the ignition lead, dis-
assemble the flywheel (4.4.4) and
ignition armature (4.4.5.3). Unscrew
on the high-tension output of the
armature. Take off the rubber boot and
then pull out the ignition lead through
the cable clamp and crankcase. Use a
suitable pair of pliers to grip and pull
the leg spring out of the ignition lead
terminal. Then pull ignition lead out of
the terminal.
25