Husqvarna 966976701 manual Maintenance, Carburettor

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MAINTENANCE

Carburettor

Your Husqvarna product has been designed and manufactured to specifications that reduce harmful emissions. After the engine has used 8-10 tanks of fuel the engine will be run-in. To ensure that it continues to run at peak performance and to minimise harmful exhaust emissions after the running-in period, ask your dealer/ service workshop (who will have a rev counter at their disposal) to adjust your carburettor.

WARNING! The complete clutch cover

! and shaft must be fitted before the machine is started, otherwise the clutch can come loose and cause personal injury.

Function

The carburettor governs the engine’s speed via the throttle control. Air and fuel are mixed in the carburettor. The air/fuel mixture is adjustable. Correct adjustment is essential to get the best performance from the machine.

Adjusting the carburettor means that the engine is adapted 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 jet

H = High speed jet

T = Idle adjustment screw

The L and H-jets are used to adjust the supply of fuel to match the rate that air is admitted, which is controlled with the throttle. If they are screwed clockwise the air/fuel ratio becomes leaner (less fuel) and if they are turned anti-clockwise the ratio becomes richer (more fuel). A lean mixture gives a higher engine speed and a rich mixture gives a lower engine speed.

The T-screw regulates the throttle setting at idle speed. If the T-screw is turned clockwise this gives a higher idle speed; turning it anti-clockwise gives a lower idle speed.

Basic setting

The basic carburettor settings are adjusted during testing at the factory. The basic setting is richer than the optimal setting and should be maintained for the first few hours the machine is in use. The carburettor should then be finely adjusted. Fine adjustment should be carried out by a skilled technician.

CAUTION! If the cutting attachment rotates when the engine is idling the idle adjustment screw T should be turned anti-clockwise until the cutting attachment stops.

Rec. idle speed: 2700 rpm

Recommended max. speed: See the Technical data section.

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.

Fine adjustment

When the machine has been ”run-in” the carburettor should be finely adjusted. The fine adjustment should be carried 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 air filter is clean and the air filter cover is fitted. If you adjust the carburettor when the air filter is dirty it will result in a leaner mixture when the filter is finally cleaned. This can lead to serious engine damage.

Carefully turn both jets, L and H, so that they are midway between fully screwed in and fully screwed out.

Do not attempt to adjust the L and H jets beyond either stop as this could damage the engine.

Now start the machine according to the starting instructions and let it warm up for 10 minutes.

CAUTION! If the cutting attachment rotates when the engine is idling the idle adjustment screw T should be turned anti-clockwise until the cutting attachment stops.

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Contents 327P4 327P5X-series Symbols KEY to SymbolsContents Dear Customer IntroductionWhat is what? What is WHAT?Personal protective equipment General Safety PrecautionsThrottle lockout Machine′s safety equipmentVibration damping system Stop switchMuffler Cutting equipment Quick release Balance Flex harnessOnly use cutting equipment recommended by us Specification of bar and saw chain Sharpening your chain and adjusting raker clearanceChain General Safety Precautions Tensioning the chain Lubricating cutting equipment Adjusting chain lubricationFilling with chain oil Checking chain lubricationWhat to do if lubrication does not work Checking wear on cutting equipment ChainChain drive sprocket May increase the risk of accidentsAdjusting the harness AssemblyFitting the cutting head Fitting the bar and chainFilling with oil AssemblyAssembling and dismantling the two-piece shaft Fitting the impact guardAssembly of the saw attachment Fuel Handling Fuel safetyFuel Mixing FuellingCheck before starting Starting and StoppingStarting and stopping StartingStopping Safety instructions while working Safety instructions regarding the surroundingsWorking Techniques General working instructionsBasic working techniques Safety instructions after completing workWithout having the cutting attachment in full view Carburettor MaintenanceCorrectly adjusted carburettor Fine adjustment of the idle speed TLow speed jet L High speed jet HCooling system MufflerSpark plug Is damaged it should be replacedTwo-piece shaft Cleaning the air filterAir filter Oiling the air filterMaintenance Daily Weekly Monthly Maintenance scheduleTechnical data Technical DataEC-declaration of conformity Applies to Europe only Approved accessories Art No Use withBar and chain combinations Page Page Page Page 1150991-26