Husqvarna RS52 用户手册

26 – 

English

Your Jonsered product has been designed and manufactured 
to specifications that reduce harmful exhaust fumes. The 
engine will be run in after it has used 8-10 tanks of fuel. To 
ensure that the engine runs at peak performance and 
produces as little harmful exhaust fumes as possible after the 
running-in period, ask your dealer/service workshop (which 
has a rev counter for this purpose) 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 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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Adjusting the carburettor means that the engine is 
adapted to local operating conditions, e.g. climate, 
altitude, petrol and the type of 2-stroke oil.

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The carburettor 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 carburettor 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

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.

Try to find the highest idle speed by turning the low speed jet 
L clockwise then anti-clockwise. When the highest speed has 
been found, turn the low speed jet L 1/4 turn anti-clockwise.

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.

L

+ 1/4