26
English / USA
FS 75
If the engine is low on power, check the 
spark arresting screen in the muffler.
: Lift spark arresting screen and pull it 
out sideways.
: Clean spark arresting screen if 
necessary.
: If screen is damaged or coked up, fit 
a new one.
: Refit the spark arresting screen.
* see “Guide to Using this Manual”
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.
Spark Arresting Screen* in 
Muffler
392BA035 KN
Checking the Spark Plug
000BA002 KN