Husqvarna 343F, 345FX, 345FXT, 343R, 345RX Tachometer should always be used to find the optimal

3		Fuel system
		When checking the speed on a
			NOTE!
		trimmer no part of the cord
			A tachometer should always be used to find the optimal
		should be extended.
		Use the 502 71 14-01 tachom-	setting.
			The recommended max. speed must not be exceeded.
		eter to check the speed.
502 71 14-01		• Carefully screw in (clock-
		wise) the L- and H-jets until
			Idling speed T-screw
		they bottom. Now screw out
		(anticlockwise) the needles	Let the engine idle for about 30 seconds or until the speed has
		1 turn. The carburettor now	stabilised. Adjust the idling speed T-screw until the engine
		has the setting H = 1 and	idles without stopping.
		L = 1.	• Turn the screw clockwise if the engine stops.
		Use special screwdriver 501
			• Turn the screw anticlockwise to lower the speed.
	501 60 02-03	60 02-03.
• Start the engine and run warm for 10 minutes.			Correctly adjusted carburettor
			A correctly adjusted carburettor means that the engine
Low speed jet L			accelerates without hesitation and it “splatters” a little at full
			throttle.
Find the highest idling speed by slowly turning the low speed
			• A too lean adjusted L-needle can cause starting difficulties
needle clockwise and anticlockwise. When the highest speed
			and poor acceleration.
has been found, turn the L-needle 1/4 turn anticlockwise.
			• A too lean adjusted H-needle results in lower power, poor
High speed jet H			acceleration and/or damage to the engine.
			• A too rich setting of the “L” and “H” needles give accelera-
The high-speed H-needle affects the engine’s power and
			tion problems or a too low working speed.
speed. A too lean H-needle setting (H-needle screwed in too
far) gives too little fuel to the engine resulting in damage to			NOTE!
the engine.			If the cutting equipment rotates while idling the T-
Run the engine at full throttle for about 10 seconds. The H-			screw should be turned anticlockwise until it stops.
needle is set correctly when the engine “splatters” a little.

If the muffler smokes heavily, at the same time as the engine “splatters” a great deal, the setting is too “rich”. Turn the H- needle clockwise until you find the setting that sounds right.

Carburettors in E-Tech and CARB-EPA designs (CARB II-EPA II only applies to USA and Canada)

On these types of carburettor the H- and L-needles can be adjusted within ex- tremely tight limits, to among other things, comply with the stringent demands with regard to the hydrocarbon and nitrogen oxide content in the exhaust fumes.

The carburettor needles on these carburettors are fitted with plastic sleeves with movement limiters, so-called caps.

To carry out adjustment when replacing needles or the entire carburettor the engine must be under load. This is achieved by fitting a Trimmy Fix with the specified length and diameter of trimmer cord. Consequently, the stated speed will be much lower than with “normal” carburettor adjustment when the engine may run freely.

After replacing the needles or the entire carburettor on a CARB-EPA approved engine, adjustment must be carried out according to the instructions below.

The combiguard or trim guard must be fitted when adjusting the H-needle.

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