Fine adjustment of the idle speed T

MAINTENANCE

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 without a load (Blade can be used)

The machine is equipped with speed control in the ignition system. It is extremely important to be aware of this when adjusting the carburettor.

343R, 345RX: Speed control at: 12500 rpm

343F, 343FR, 345FX, 345FXT: Speed control at: 13500 rpm

When attempting to adjust the speed over that speciﬁed, the speed is not changed, but only causes the engine to receive too little fuel resulting in a large risk of engine failure.

Run the machine warm for approximately 5 minutes alternating between short intervals of full throttle and idling. When the carburettor is to be adjusted, apply full throttle and turn the H-needle anti-clockwise until the engine speed reaches 10,500-11,000 r/min (burbles) or until the cap reaches its stop position. Now turn the H-needle slowly clockwise until the engine reaches the speed when the speed control comes into force. In some cases, speed control can come into force at 200-300 revs below or above that speciﬁed. It is important that you do not continue to turn the H-needle clockwise when the engine speed has stabilised. Screw the H-needle (anti-clockwise) a few tenths of a turn instead.

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.

Run the machine warm for about 5 minutes mostly at full throttle. When the carburettor is to be adjusted, apply full throttle and turn the H-needle anti-clockwise until the engine burbles or until the cap reaches its stop position. (If the engine runs smoothly when the cap is in its stop position no further adjustment is necessary!) Turn the H-needle slowly clockwise until the engine runs absolutely smoothly. (Burbling has stopped completely). Now screw the H-needle (anti- clockwise) a few tenths of a turn.

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 (343FR, 343R, 345RX)

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.

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.

28 – English