Hitachi CS25EPA Owner's Manual page 12

Air filter (Fig. 3-2)
The air filter must be cleaned from dust and dirt
in order to avoid:
Carburetor malfunctions.
Starting problems.
Engine power reduction.
Unnecessary wear on the engine parts.
Abnormal fuel consumption.
Clean the air filter daily or more often if working
in exceptionally dusty areas.
Cleaning the air filter
Remove the air filter cover and the filter (1).
Rinse it in warm soap suds. Check that the filter
is dry before reassembly. An air filter that has
been used for some time cannot be cleaned
completely. Therefore, it must regularly be
replaced with a new one. A damaged filter must
always be replaced.
Fuel filter (Fig. 3-2B)
Drain all fuel from fuel tank and pull fuel filter line
from tank. Pull filter element out of holder
assembly and rinse element in warm water with
detergent.
Rinse thoroughly until all traces of detergent are
eliminated. Squeeze, do not wring, away excess
water and allow element to air dry.
Fig.3-2
Fig.3-3
NOTE!
If element is hard due to excessive dirt build-up,
replace it.
Chain oil filter (Fig. 3-2C)
Remove the oil filter and thoroughly wash it in
solvent
Spark plug (Fig. 3-3)
The spark plug condition is influenced by:
An incorrect carburetor setting.
Wrong fuel mixture (too much oil in the gasoline)
A dirty air filter.
Hard running conditions (such as cold
weather).
These factors cause deposits on the spark plug
electrodes, which may result in malfunction and
starting difficulties. If the engine is low on
power, difficult to start or runs poorly at idling
speed, always check the spark plug first. If the
spark plug is dirty, clean it and check the
electrode gap. Readjust if necessary. The
correct gap is 0.6 mm. The spark plug should
be replaced after about 100 operation hours or
earlier if the electrodes are badly eroded.
Fig.3-2B
Fig.3-5
NOTE!
In some areas, local law requires using a
resistor spark plug to suppress ignition signals.
If this machine was originally equipped with
resistor spark plug, use same type of spark
plug for replacement.
Muffler (Fig. 3-4)
Remove the muffler and clean out any excess
carbon from the exhaust port or muffler inlet
every 100 hours of operation.
Cylinder (Engine cooling) (Fig. 3-5)
The engine is air cooled and air must circulate
freely around engine and over cooling fins on
cylinder head to prevent overheating.
Every 100 operating hours, or once a year
(more often if conditions require) clean fins and
external surfaces of engine of dust, dirt and oil
deposits which can contribute to improper cooling.
NOTE!
Do not operate engine with engine shroud or
muffler guard removed as this will cause
overheating and engine damage.
Fig. 3-2C
Fig.3-4
GB-11