Bäumr-AG Petrol Powered Lawn Mowers
E&OE
©2017 Bäumr-AG
19
Spark Plug
If the spark plug is damaged (cracked insulator, broken or eroded electrodes etc), replace it. •
Always use spark plugs of the correct “heat range” - see
The spark plug is used to ignite the air/fuel mixture inside the engine. The spark plug has electrodes on one
end and an electrical terminal on the other. The spark plug requires regular maintenance.
Spark Plug Cleaning and Gap Checking
The spark plug should be checked and cleaned as per the maintenance schedule.
1. Remove any carbon deposits on the spark plug (
A
) electrodes (
B
) with a wire
brush.
2. Clean the spark plug threads and the electrical terminal (
C
) on the top.
To check and adjust the spark plug “gap”:
1. Use “feeler” or “thickness” gauges (
X
) to measure the existing gap. The gauge
must drag a little when being slid between the electrodes (
B
) – this means the
measurement is fairly accurate.
2. Adjust the gap to within specification (see
). If the gap needs to be
reduced, gently tap the electrode as required. If the gap needs to be increased,
use pliers to gently pull the electrode as required.
3. Measure the gap again and ensure it is within the specified range before re-installing the spark plug.
Spark Plug Removal/Installation
1. Pull the electrical lead (
A
) from the terminal on top of the spark
plug (
B
).
2. Clean the area around the spark plug so that no dirt or other
material can enter the engine when the spark plug is removed.
3. Use the spark plug tool (
C
) to remove the spark plug (rotate left).
To re-install the spark plug:
1. Place the spark plug in its hole and screw it in (rotate right) until
“finger tight”.
2. Use the spark plug tool to tighten the spark plug approximately
one quarter turn (do not over-tighten).
3. Place the electrical lead over the spark plug terminal and push it
down so that it connects firmly terminal.
A
B
B
X
C
A
B
C
