Husqvarna 250 R 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.

The carburettor can be designed in different ways, depending 
on the existing environmental and emissions legislation. 
Some machines are equipped with movement limiters on the 
carburettor’s adjuster screws. These limit the adjustment 
range to a maximum of 1/2 turn.

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The carburetor governs the engine’s speed via the throttle 
control. Air and fuel are mixed in the carburetor. 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 
adapted to local conditions, for example, the climate, 
altitude, fuel and the type of 2-stroke oil.

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The carburetor has three adjustment controls:

L = Low speed jet

H = High speed jet

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.

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The basic carburetor settings are adjusted during testing 
at the factory. The basic setting is richer than the optimal 
setting and should be maintained for the first few hours the 
machine is in use. The carburettor should then be finely 
adjusted. Fine adjustment should be carried out by a 
skilled technician.

The basic setting can vary between: H = 1 - 1 1/4 turns 
and L = 1 - 1 1/4 turns.

CAUTION!  If the cutting attachment rotates when the engine 
is idling the idle adjustment screw T should be turned anti-
clockwise until the cutting attachment stops.

Rec. idle speed 2700 rpm

Rec. idle speed 2250 rpm

CAUTION!  The machine should only be run for short periods 
at its highest speed. For optimum adjustment of the 
carburettor, contact a qualified dealer/service workshop that 
has a revolution counter at their disposal. 

Recommended max. speed: See the Technical data section.

During the running-in period (8-10 tanks of fuel) the maximum 
speed should be set 600-700 rpm below the recommended 
maximum speed (= open the high speed jet H a further 1/8 
turn).

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Before any adjustments are made, make sure that the air 
filter is clean and the air filter cover is fitted. If you adjust 
the carburettor when the air filter is dirty it will result in a 
leaner mixture when the filter is finally cleaned. This can 
lead to serious engine damage.

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Carefully turn both jets, L and H, so that they are midway 
between fully screwed in and fully screwed out.

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Do not attempt to adjust the L and H jets beyond either 
stop as this could cause damage.

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Now start the machine according to the starting 
instructions and let it warm up for 10 minutes.

CAUTION!  If the cutting attachment rotates when the engine 
is idling the idle adjustment screw T should be turned anti-
clockwise until the cutting attachment stops.