Husqvarna 325HDA55X-series Operator's Manual

Also see for 325HDA55 x-series, 325HE3, 325HE3 x-series, 325HE4 x-series: Operator's manual Operator's manual Operator's manual Operator's manual

Contents

16 – EnglishMAINTENANCECarburettorYour Husqvarna product has been designed andmanufactured to specifications that reduce harmfulemissions. After the engine has used 8-10 tanks of fuel theengine will be run-in. To ensure that it continues to run at peakperformance and to minimise harmful exhaust emissionsafter the running-in period, ask your dealer/service workshop(who will have a rev counter at their disposal) to adjust yourcarburettor.Function• The carburettor governs the engine’s speed via thethrottle control. Air and fuel are mixed in the carburettor.The air/fuel mixture is adjustable. Correct adjustment isessential to get the best performance from the machine.• Adjusting the carburettor means that the engine isadapted to local operating conditions, e.g. climate,altitude, petrol and the type of 2-stroke oil.• The carburettor has three adjustment controls:L = Low speed jetH = High speed jetT = Idle adjustment screw• The L and H-jets are used to adjust the supply of fuel tomatch the rate that air is admitted, which is controlled withthe throttle. If they are screwed clockwise the air/fuel ratiobecomes leaner (less fuel) and if they are turned anti-clockwise the ratio becomes richer (more fuel). A leanmixture gives a higher engine speed and a rich mixturegives a lower engine speed.• The T-screw regulates the throttle setting at idle speed. Ifthe T-screw is turned clockwise this gives a higher idlespeed; turning it anti-clockwise gives a lower idle speed.Basic setting• The basic carburettor settings are adjusted during testingat the factory. The basic setting is richer than the optimalsetting and should be maintained for the first few hours themachine is in use. The carburettor should then be finelyadjusted. Fine adjustment should be carried out by askilled technician.CAUTION! If the cutting attachment rotates when the engineis idling the idle adjustment screw T should be turned anti-clockwise until the cutting attachment stops.Rec. idle speed 2700 rpmRecommended max. speed: See the Technical data section.Fine adjustment• When the machine has been ”run-in” the carburettorshould be finely adjusted. The fine adjustment should becarried out by a qualified person. First adjust the L-jet,then the idling screw T and then the H-jet.Conditions• Before any adjustments are made, make sure that the airfilter is clean and the air filter cover is fitted. If you adjustthe carburettor when the air filter is dirty it will result in aleaner mixture when the filter is finally cleaned. This canlead to serious engine damage.• Carefully turn both jets, L and H, so that they are midwaybetween fully screwed in and fully screwed out.• Do not attempt to adjust the L and H jets beyond eitherstop as this could cause damage.• Now start the machine according to the startinginstructions and let it warm up for 10 minutes.CAUTION! If the cutting attachment rotates when the engineis idling the idle adjustment screw T should be turned anti-clockwise until the cutting attachment stops.Low speed jet LTry to find the highest idle speed by turning the low speed jetL clockwise then anti-clockwise. When the highest speed hasbeen found, turn the low speed jet L 1/4 turn anti-clockwise.CAUTION! If the cutting attachment rotates when the engineis idling the idle adjustment screw T should be turned anti-clockwise until the cutting attachment stops.Fine adjustment of the idle speed TAdjust the idle speed with the idle adjustment screw T, ifadjustment is necessary. First turn the idle adjustment screwT clockwise until the blades start to move. Then turn the idleadjustment screw T anticlockwise until the blades stop. Theidle speed is correctly adjusted when the engine runssmoothly in every position. There should also be a clearmargin to the speed at which the blades start to move.! WARNING! The complete clutch cover andshaft must be fitted before the machine isstarted, otherwise the clutch can come looseand cause personal injury.! WARNING! If the idle speed cannot beadjusted so that the cutting attachmentstops, contact your dealer/serviceworkshop. Do not use the machine until ithas been correctly adjusted or repaired.L+ 1/4