— US-18 —
Cylinder Cooling Fins
Maintenance Interval
• The cylinder cooling fins should be cleaned after
every 25 hours of operation, or once a week,
whichever comes first.
• Air must flow freely around and through the
cylinder cooling fins to prevent engine
overheating. Leaves, grass, dirt and debris buildup
on the fins will increase the operating temperature
of the engine, which can reduce engine
performance and shorten engine life.
Cooling Fin Cleaning
1. With the engine at ambient (room) temperature,
loosen the knob and remove the air filter cover.
2. Twist the high tension lead boot on the spark plug
back and forth a couple of times to loosen the
boot, then pull the boot off of the spark plug.
3. Loosen the knob and lift off the cylinder cover.
4. Clean all dirt and debris from the cooling fins and
from around the cylinder base.
5. DO NOT overlook cleaning of the cooling air
intake area below the crankcase and above the
fuel tank! This area must be free of debris and
obstruction for the engine to cool properly.
6. Reinstall the cylinder cover and the air filter
cover.
Spark Arrester
Maintenance Interval
• The spark arrester should be inspected and cleaned
after every 25 hours of use.
• Replace the screen if it cannot be thoroughly
cleaned, or if it is damaged.
Spark Arrester Maintenance
1. With the engine at ambient (room) temperature,
loosen the knob and remove the air filter cover.
2. Twist the high tension lead boot on the spark plug
back and forth a couple of times to loosen the
boot, then pull the boot off of the spark plug.
3. Loosen the knob and lift off the cylinder cover.
4. Remove and clean the tail, gasket and spark
arrester with a safety solvent and a stiff brush. If
any part cannot be thoroughly cleaned, it must be
replaced.
WARNING
POTENTIAL HAZARD
• Muffler surface becomes hot when
Hedge trimmer is in operation and
remains hot for sometime after the
engine is shut off.
WHAT CAN HAPPEN
• Contact with hot muffler surfaces could
cause a burn.
HOW TO AVOID THE HAZARD
• Make sure the muffler is cool before
inspecting and cleaning the spark
arrester.
Spark Arrester
Socket Head Screw
Tail
High Tension Lead Boot
Cylinder Cover
Cooling Fins
Knob
Knob
Air Filter Cover
