MAINTENANCE
Fine adjustment of the idle speed T
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.
WARNING! If the idle speed cannot be
!adjusted so that the cutting attachment stops, contact your dealer/service workshop. Do not use the machine until it has been correctly adjusted or repaired.
High speed jet H
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.
Setting procedure with a load (Trimmer head should be used)
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.
H 
CAUTION! For optimum adjustment of the carburettor, contact a qualified dealer/service workshop that has a revolution counter at their disposal.
Correctly adjusted carburetor
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.
Adjusting the start throttle speed (BC2255)
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
mmAllen screw) to increase or decrease the start throttle speed.
4 mm
Proceed as follows:
1Run the machine at idle.
2Press the start throttle lock as described under the heading Starting and stopping.
3If the start throttle speed is too low (below 4000 rpm), turn the adjuster screw A clockwise until the cutting attachment starts to rotate. Then turn A clockwise a further 1/2 turn.
4If the start throttle speed is too high, turn the adjuster screw A anticlockwise until the cutting attachment stops. Then turn adjuster screw A clockwise a further 1/2 turn.
Muffler
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.
English – 27
