Husqvarna 346XP EPA II 用户手册

30 – 

English

Your Husqvarna product has been designed and 
manufactured to specifications that reduce harmful 
emissions. After the engine has used 8-10 tanks of fuel the 
engine will be run-in. To ensure that it continues to run at peak 
performance and to minimise harmful exhaust emissions after 
the running-in period, ask your dealer/service workshop (who 
will have a rev counter at their disposal) to adjust your 
carburettor.

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The carburettor governs the engine’s speed via the 
throttle control. Air and fuel are mixed in the carburettor. 
The air/fuel mixture is adjustable. Correct adjustment is 
essential to get the best performance from the machine.

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The setting of the carburetor means that the engine is 
adepted to local conditions, for example, the climate, 
altitude, fuel and the type of 2-stroke oil.

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The carburettor has three adjustment controls: 

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L = Low speed jet

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H = High speed jet

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T = Idle adjustment screw

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The L and H-jets are used to adjust the supply of fuel to 
match the rate that air is admitted, which is controlled with 
the throttle. If they are screwed clockwise the air/fuel ratio 
becomes leaner (less fuel) and if they are turned anti-
clockwise the ratio becomes richer (more fuel). A lean 
mixture gives a higher engine speed and a rich mixture 
gives a lower engine speed.

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The T-screw regulates the throttle setting at idle speed. If 
the T-screw is turned clockwise this gives a higher idle 
speed; turning it anti-clockwise gives a lower idle speed.

The carburettor is set to its basic setting when test run at the 
factory. The basic setting is richer than the optimum setting 
and should be maintained for the first hours that the machine 
is in use. The carburettor should then be finely adjusted. Fine 
adjustment should be carried out by a suitably trained person.

CAUTION!  If the chain rotates while idling the T-screw 
must be turned anti-clockwise until the chain stops.

Rec. idle speed: 2700 rpm

When the machine has been ”run-in” the carburettor should 
be finely adjusted. The fine adjustment should be carried 
out by a qualified person. First adjust the L-jet, then the 
idling screw T and then the H-jet.

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Before any adjustments are made the air filter should be 
clean and the cylinder cover fitted. Adjusting the 
carburettor while a dirty air filter is in use will result in a 
leaner mixture next time the filter is cleaned. This can give 
rise to serious engine damage.

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Carefully turn the L and H needle to the mid point.

•

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Now start the machine according to the starting 
instructions and let it warm up for 10 minutes. CAUTION! 
If the chain rotates while idling the T-screw must be 
turned anti-clockwise until the chain stops.

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Place the machine on a flat surface so that the bar points 
away from you and so that the bar and chain do not come 
into contact with the surface or other objects.

Turn the low speed jet L clockwise until it stops. If the engine 
accelerates poorly or idles unevenly, turn the low speed jet L 
anticlockwise until good acceleration and idling are achieved.

CAUTION! If the chain rotates while idling the T-screw 
must be turned anti-clockwise until the chain stops.

Adjust the idle speed with the T-screw. If it is necessary to re-
adjust, turn the T-screw clockwise while the engine is running, 
until the chain starts to rotate. Then turn counter-clockwise 
until the chain stops. A correctly adjusted idle speed setting 
occors when the engine runs smoothly in every position. It 
should also be good margin to the rpm when the chain starts 
to rotate.

The high speed needle H influence the power of the machine. 
A too lean adjusted high speed (high speed needle H turn too 
much clockwise) gives overrevs and damages the engine. Do 
not allow the engine to run at full speed for more than 10 
seconds. Turn the high speed needle H counter-
clockwiseuntil the stop. If the engine runs roughly, turn the 
high speed needle slowly the minimum amount clockwise 
until the engine runs smoothly. The high speed needle H is 
correctly set when the saw “4-cycles” a little. If the machine 
“whistles“ the setting is too lean. If there is too much exhaust