Husqvarna 343FRM User Manual

30 – English

Try to find the highest idling speed, turning the low speed 
needle L clockwise respectively counter-clockwise. When 
the highest speed has been found, turn the low speed 
needle L 1/4 turn counter-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.

Adjust the idle speed using the idle adjustment screw T, if 
it is necessary to readjust. First turn the idle adjustment 
screw T clockwise until the cutting attachment starts to 
rotate. Then turn the screw anticlockwise until the cutting 
attachment stops. The idle speed is correctly adjusted 
when the engine will run smoothly in every position. The 
idle speed should also be well below the speed at which 
the cutting attachment starts to rotate.

The high speed jet H affects the engine power, speed, 
temperature and fuel consumption. If the high speed jet H 
is set too lean (screwed in too far) the engine speed will 
be too high and cause engine damage. Do not let the 
engine run at full speed for more than 10 seconds.

Ensure the length of the trimmer cord is correct, i.e. 
exactly reaches the knife on the trimmer guard. Use either 
3 mm or 3.3 mm diameter trimmer cord.

Apply full throttle and turn the high speed jet H very slowly 
clockwise until the engine slows down. Then turn the high 
speed jet H very slowly anticlockwise until the engine 
starts to run unevenly. Now turn the high speed jet H 
slowly clockwise a little way until the engine runs 
smoothly. 

CAUTION!  For optimum adjustment of the carburettor, 
contact a qualified dealer/service workshop that has a 
revolution counter at their disposal. 

When the carburetor is correctly adjusted the machine will 
accelerate without hesitation and burble a little at 
maximum speed. It is also important that the cutting 
attachment does not rotate at idle. If the low speed jet L is 
set too lean it may cause starting difficulties and poor 
acceleration. If the high speed jet H is set too lean it will 
result in less power, less performance, poor acceleration 
and/or damage to the engine. If both the L and H jets are 
set too rich it will results in acceleration problems or too 
low a working speed.

The correct start throttle speed is set by means of an 
adjuster on the rear of the handle next to the cable. Use 
this screw (5 mm Allen screw) to increase or decrease the 
start throttle speed.

H