Husqvarna 426LST ユーザーズマニュアル

English

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 17

Check that the air filter is clean. When the idle speed is 
correct, the cutting attachment should not rotate. If 
adjustment is required, close (turn clockwise) the idle 
adjustment screw T, with the engine running, until the 
cutting attachment starts to rotate. Open (turn 
anticlockwise) the screw until the cutting attachment 
stops. The idle speed is correctly set when the engine 
runs smoothly in all positions, and there is a clear margin 
to the speed at which the cutting attachment starts to 
rotate.

CAUTION!  Some mufflers are fitted with a catalytic 
converter. See chapter on Technical data to see whether 
your machine is fitted with a catalytic converter.

The muffler is designed to reduce the noise level and to 
direct the exhaust gases away from the operator. The 
exhaust gases are hot and can contain sparks, which may 
cause fire if directed against dry and combustible 
material.

Some mufflers are equipped with a special spark arrestor 
screen. If your machine has this type of muffler, you 
should clean the screen at least once a week. This is best 
done with a wire brush.

 On mufflers without a catalytic converter the screen 
should be cleaned weekly, or replaced if necessary. On 
mufflers fitted with a catalytic converter the screen should 
be checked, and if necessary cleaned, monthly. If the 
screen is damaged it should be replaced. If the screen 
is frequently blocked, this can be a sign that the 
performance of the catalytic converter is impaired. 
Contact your dealer to inspect the muffler. A blocked 
screen will cause the machine to overheat and result in 
damage to the cylinder and piston.

CAUTION!  Never use a machine with a defective muffler.

To keep the working temperature as low as possible the 
machine is equipped with a cooling system.

The cooling system consists of:

1

Cooling fins on the cylinder.

2

Cooling air intake

Clean the cooling system with a brush once a week, more 
often in demanding conditions. A dirty or blocked cooling 
system results in the machine overheating which causes 
damage to the piston and cylinder.

The spark plug condition is influenced by:

•

Incorrect carburetor adjustment.

•

An incorrect fuel mixture (too much or incorrect type 
of oil).

•

A dirty air filter.

These factors cause deposits on the spark plug 
electrodes, which may result in operating problems and 
starting difficulties.

If the machine is low on power, difficult to start or runs 
poorly at idle speed: always check the spark plug first 
before taking any further action. If the spark plug is dirty, 
clean it and check that the electrode gap is 0,6-0,7 mm 
(426LST) / 0,9-1,0 mm (430LS). The spark plug should be 

H1153174-95,426LST,430LS,US.fm  Page 17  Monday, November 30, 2009  10:56 AM