Husqvarna 343F, 345FX, 345FXT, 343R, 345RX manual Crankshaft and crankcase

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Crankshaft and crankcase

 

 

 

 

 

 

 

The task of the crankshaft is to transform the reciprocating

The crankshaft is journalled in the crankcase on

 

motion of the piston to rotation. This requires a stable

heavy-duty ball bearings. In addition to the journalling

 

design withstanding immense pressure and rotational and

point for the crankshaft, the crankcase acts as a

 

bending strain, as well as high rotational speed. In addition

scavenging pump for the fuel/air mixture when this is

 

the connecting rod is exposed to large acceleration and

“sucked” from the carburettor and is forced into the

 

retardation forces as it moves between the top and bottom

cylinder’s combustion chamber. The crankcase must

 

dead centres. This puts special demands on the bearings

be perfectly sealed so as not to affect this pump

 

that must withstand quick changes in load. Moreover, the

function. There cannot be any leakage from the crank-

 

bearing’s roller retainer must also cope with high tempera-

shaft, between the crankcase halves or between the

 

tures and friction. It is therefore extremely important when

crankcase and the cylinder.

 

servicing to check the roller retainer for cracks, wear and

Always replace the sealing rings and gaskets when

 

discolouration caused by overheating.

servicing the crankcase.

 

 

 

 

 

 

 

 

Dismantling

Dismantle all components so that only the crankcase and crankshaft remain.

Dismantle the guard under the crank- case.

Bend away the heat guard (A) and cable guide (B).

Dismantling

Dismantle all components so that only the crankcase and crankshaft remain.

See the respective sections for detailed information if necessary.

Remove the 4 bolts and lift off the guard from under the crankcase.

Bend away the heat guard (A) with your fingers and carefully push the cable guide (B) aside with a screwdriver.

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Remove the 4 bolts holding the crank- case halves together.

502 50 18-01

Remove the 4 bolts holding the crank- case halves together.

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Contents English Workshop Manual Brushcutter, Trimmer Model 343R, 345RX, 343F, 345FX, 345FXT ContentsGeneral recommendations Starter ContentsDismantling 1StarterStarter AssemblyReplacing the drive dogs Electrical system 502 71 Electrical systemChecking the ignition spark Tip 502 50 Replacing the spark Plug cover502 54 Heated handles Drive dogsWiring diagram Electrical system Fuel system Air filter Fuel systemFuel filter Tank ventingDismantling Fuel pumpCarburettor Blending unit Carburettor’s designMetering unit Dismantling the carburettor Pump unitFuel system Little shorter than the L-needle PositionedFor example, the H-needle is a Assembling the carburettor Than the L-needle H-needle is a little shorterCheck carefully that the fuel hoses Are not bent or pinched whenFine adjustment Carburettor settingsBasic setting Correctly adjusted carburettor Setting Recommended max. speed must not be exceededTachometer should always be used to find the optimal Idling speed T-screwAdjusting the L-needle Adjusting the H-needle Carburettor adjustment 345RX/FXThrottle RotatingCheck for wear on pins a and B Tip Page Centrifugal clutch 502 21 Centrifugal clutchDo not lose the sleeve bearings found in the clutch shoes Centrifugal clutch502 11 Clutch drumChange the bearings in the clutch housing if necessary Page Angle gear Let the small circlip around the axle remain Angle gearInput axle with pinion must be dismantled first 503 97503 80 ShaftCylinder and piston Cylinder and piston Decompression valve Turn the valve the right way when fittingWhen the valve is fitted the small hole must face outwards Inlet manifold Cleaning, inspectionCause Action Analysis and actionsInsufficient lubrication Piston scoring caused by heavy carbon deposits Piston ring breakage Piston damage caused by a too high engine speedCause Foreign objectsDefect Action Service tipsWear tolerances Crankshaft and crankcase Crankshaft and crankcase 502 52 Crankshaft and crankcaseInspecting Crankshaft Assembly Press down the sealing plates as Leakage testing CrankcaseFar as possible between the bolts To ensure a proper seal503 55 Husqvarna E-Tech
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