Service Manual

Figure 1-10. Squeezing Excess Oil From Air
Filter Element.
5. Reinstall the air filter in the carburetor/air filter
cover assembly. Refer to Part 4 - Engine Assem-
bly.
Spark Plug
Every 50 hours of operation, remove the spark plug,
check its condition, and reset the gap or replace with a
new plug as necessary.
WARNING: Electrical Shock!
Never touch electrical wires or components while the
engine is running. They can be sources of electrical
shock.
1. Before removing the spark plug, clean the area
around the base of the spark plug to keep dirt and
debris out of the engine.
2. Disconnect the spark plug wire and remove the
spark plug from engine.
3. Inspect the spark plug for carbon buildup and clean
if necessary. Replace the plug if it is badly burnt or
if reuse is questionable.
NOTE: Do not clean the spark plug in a machine
which uses abrasive grit. Some grit could remain
on the spark plug and enter the engine causing
extensive damage.
4. Check the spark plug gap using a wire feeler gauge.
Set the gap to 0.025 inch (0.635 mm) (Figure 1-
11).
5. Reinstall the spark plug and torque to 190-210 in•lb
(21.4-23.6 N•m).
Figure 1-11. Spark Plug Gap.
Carburetor Adjustment
These engines are equipped with a diaphragm-type
carburetor. The carburetor has been carefully cali-
brated at the factory. In most cases, no further adjust-
ment will be required.
The condition of the air filter is very important to the op-
eration of the trimmer. A dirty air filter will restrict the
air flow to the carburetor. This in turn upsets the fuel-
air mixture in the carburetor. The resulting symptoms
are often mistaken for an out-of-adjustment carburetor.
Therefore, check the condition of the air filter before
adjusting the carburetor. Refer to “Air Filter” Serv-
ice/Maintenance Instructions.
If the following conditions are experienced, it may be
necessary to adjust the carburetor.
• The engine will not idle.
• The engine hesitates or stalls on acceleration.
• The loss of engine power, which is not corrected
by cleaning the air filter.
• The engine operates in an erratic or fuel-rich
condition (indicated by excessive exhaust smoke
from the muffler).
3.6078.010
2.6081.011
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GENERAL INFORMATION
1-12