Spark Plug Boot - Stihl MS 290 Manual

If a spark is visible, the ignition
system is in order. If no spark is
visible in the window (2), check the
ignition system with the aid of the
troubleshooting chart, b 7.6
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1
2 3
Using the ZAT 3 ignition tester
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– Before starting the test, install a
new spark plug in the cylinder
and tighten it down firmly, b 3.5
: Remove spark plug boot and
connect it to terminal (2).
: Attach ground terminal (1) to the
spark plug.
: Use adjusting knob (4) to set
spark gap to about 2 mm.
: If a spark is visible in window (3),
the ignition system is in order.
40
While using the ZAT 3, hold it only
by the handle (4) or position it in a
safe place. Keep fingers or other
parts of your body at least 1 cm
away from the spark window (3),
high voltage connection (2), ground
connection (5) and the ground
terminal (1).
Warning!
High voltage – risk of electrocution.
– Crank the engine quickly with the
ZAT 3
rewind starter (min. 1,000 rpm)
and check sparkover in the
tester's window (3).
Warning!
4
The engine may start and
accelerate during the test.
If a spark is visible, the ignition
system is in order.
If no spark is visible in the
window (3), check the ignition
system with the aid of the
troubleshooting chart, b 7.6
7.2

Spark Plug Boot

– Troubleshooting – b 4.4
– Remove the handle housing, b
9.2
– Pull the boot off the spark plug.
: Use suitable pliers to pull the leg
spring out of the spark plug boot.
– Unhook the leg spring from the
ignition lead.
– Pull the boot off the ignition lead.
– Cut new ignition lead to a length
of 175 mm.
– Coat end of ignition lead (about
20 mm) with oil.
– Fit the spark plug boot over the
ignition lead.
Install in the reverse sequence.
MS 290, MS 310, MS 390