Husqvarna 250 PS Workshop Manual

Also see for 250PS: Operator's manual

Contents

213!Carburettor operation and adjustmentWARNING! Never start the pruning saw if thehydraulic oil tank and hoses are not fitted. If thehydraulic oil tank is not fitted the clutch may comeloose and cause injury. If the hoses are not fittedthe engine cannot be revved up and the hydraulicpump and clutch may be damaged.Basic settingGently screw the H and L needles all the way in. Thenopen H 1 1/4 turns and open L 1 turn. The basic settingcan vary between H=1 to 1 1/4 turns and L=1 to 1 1/4turns.NOTE! If the chain rotates at idle, turn the T screwclockwise until it stops.The basic setting is richer than the optimum setting andshould be maintained for the first 3-4 hours the saw isused. The carburettor adjustment can then be fine tuned.The carburettor controls engine speed via the throttle.Fuel is mixed with air in the carburettor. The L and Hneedles are used to adjust the amount of fuel that ismixed with air when the throttle is activated. If they areturned clockwise the fuel/air mixture is made richer(more fuel). The T screw controls the throttle setting atidle; turning it anticlockwise reduces the idle speed.! WARNING! Do not operate the pruning saw until ithas been correctly adjusted or repaired.When the carburettor is correctly adjusted the pruningsaw should accelerate smoothly without hesitating andthe engine will burble slightly at full throttle. Thisindicates that the pruning saw is working at maximumefficiency.NOTE! The chain must not rotate at idle.Before adjustingNOTE! Before making any adjustment make sure the airfilter is clean and that the hydraulic tank and hoses areconnected.Place the pruning saw on a flat surface and make surethe bar and chain are pointing away from you and cannottouch the surface or any other object.Gently screw the L and H needles clockwise all the wayin. Then unscrew both needles one turn. The carburettorsetting is now H=1 and L=1. Start the pruning saw andlet it run for ten minutes to warm up.NOTE! If the chain rotates at idle, turn the T screwclockwise until it stops.For Husqvarna Parts Call 606-678-9623 or 606-561-4983www.mymowerparts.com