8
Air fi lter (Fig. 10)
The air fi lter 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 fi lter daily or more often if working in exceptionally
dusty areas.
Fig. 10
Cleaning the air fi lter
Remove the air fi lter cover and the fi lter. Rinse it in warm soap suds.
Check that the fi lter is dry before reassembly. An air fi lter that has
been used for some time cannot be cleaned completely. Therefore,
it must regularly be replaced by a new one. A damaged fi lter must
always be replaced.
NOTE
Saturate the element in 2-cycle oil or the equivalent. Squeeze
the element to distribute the oil completely and to remove any
excess oil.
Spark plug (Fig. 11)
The spark plug condition is infl uenced by:
○ An incorrect carburetor setting.
○ Wrong fuel mixture (too much oil in the gasoline).
○ A dirty air fi lter.
○ Hard running conditions (such as cold weather).
These factors cause deposits on the spark plug electrodes, which
may result in malfunction and starting diffi culties. If the engine
is low on power, diffi cult to start or runs poorly at idling speed,
always check the spark plug fi rst. 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.
0.6 mm
Fig. 11
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 the same type of spark
plug for replacement.
Cutter blade (Fig. 12, 13)
The blades are installed to the cutter guide with the four or fi ve
bolts. Those bolts are tightened with a clearance so that the cutters
can move smoothly.
Fig. 12
Fig. 13
When clearance is too small
The cutters do not move properly and the sliding surfaces may
seize.
When clearance is too large
The cutters are poor in sharpness.
To adjust the cutter clearance
1. Loosen the cutter fi xing nuts.
2. Fully tighten the cutter fi xing bolts and then loosen them approx.
1/2 turn.
3. With the bolts set at that position, tighten the cutter fi xing nuts.
Be sure to replace cutter guide fi xing bolts when they are loosened,
worn or damaged. Also be sure to replace damaged cutter blade.
NOTE
Properly lubricate the cutter sliding surfaces with machine oil.
Gear case (Fig. 14)
Apply a good quality lithium based grease through the grease fi tting
until a small amount comes out between the cutter blades and the
gear case.
Fig. 14