Checking The Spark Plug - Stihl HS 86 Instruction Manual

English
: Use a 15 mm socket wrench to
unscrew the spark arresting
screen (3).
: Clean the spark arresting screen.
: If the spark arresting screen is
damaged or severely coked up,
fit a new one.
: Refit the spark arresting screen.
: Fit the exhaust pipe.
: Fit the screws.
18

Checking the Spark Plug

Wrong fuel mix (too much engine oil in
the gasoline), a dirty air filter and
unfavorable running conditions (mostly
at part throttle etc.) affect the condition of
the spark plug. These factors cause
deposits to form on the insulator nose
which may result in trouble in operation.
If engine is down on power, difficult to
start or runs poorly at idling speed, first
check the spark plug.
: Remove spark plug – see "Starting /
Stopping the Engine".
: Clean dirty spark plug.
: Check electrode gap (A) and
readjust if necessary – see
"Specifications".
: Use only resistor type spark plugs
of the approved range.
Rectify problems which have caused
fouling of spark plug:
: Too much oil in fuel mix.
: Dirty air filter.
: Unfavorable running conditions,
e.g. operating at part load.
Fit a new spark plug after approx.
100 operating hours
or earlier if the electrodes are badly
eroded.
HS 86 R, HS 86 T