Operator’s Manual. The assembly of other equipment or accessories or spare parts not approved by Husqvarna can Special tools result in the failure to meet these safety demands and that Some of the work described in the Workshop Manual requi- the person carrying out assembly bears responsibility for this.
Starter WARNING! Protective glasses should be worn when working on the starter to avoid injury to the eyes if, for some reason, the return spring should ﬂ y out. Dismantling Dismantling Remove the 4 bolts and lift off the starter. Remove the 4 screws and lift off the starter and the underlying guiding plate.
Starter Assembly Assembly If the return spring has, despite all the Fit the return spring in the starter housing. precautions, ﬂ own out or if you intend to ﬁ t The pressure equalisation spring is sup- a new spring proceed as follows: plied as a spare part, ﬁ...
Starter Fit the starter handle. Fit the starter handle on the cord. Run the starter cord through the handle and make a knot in the starter cord. Pull the cord into the handle. Tighten the return spring. Tighten the return spring. Check the spring tension.
Electrical system Electrical system Contents Checking the ignition spark ______________________ 8 Dismantling __________________________________ 11 Assembly __________________________________ 12...
Electrical system The engine is equipped with an electronic ignition system completely without moving parts. Con- sequently, a faulty component cannot be repaired, but must be replaced by a new component. The spark in an electronic ignition system has a very short burn time and can therefore be inter- preted as weak and can be difﬁ...
Electrical system If there is no spark, disconnect the short- If there is still no spark, separate the circuit contact . short-circuit cable which is accessible when the air ﬁ lter cover is folded out of the Replace the contact if required. way.
Electrical system Still no spark? Still no spark? Dismantle the fan housing cover with at- Dismantle the fan housing cover with at- tached starter. tached starter. Remove the 3 screws, lift off the plate (A) and then the cover. 502 50 18-01 Check other cables and connections.
Electrical system Dismantling Dismantling Dismantle the following: The following components must be dismantled for the ignition system to be The cylinder cover, the spark plug, the accessible: fan housing cover with ﬁ tted starter, the heat guard above the mufﬂ er (A) and the The cylinder cover, the spark plug, the cylinder cover (B).
Electrical system Remove the ﬂ ywheel. Dismantle the ﬂ ywheel from the crankcase using the puller no. 510 13 89-01. Gently knock the puller screw with a hammer, if the ﬂ ywheel sits tightly on the crankshaft. 510 13 89-01 Assembly Assembly Check that the key and the key slot in the...
Replace damaged ﬁ lters with a new one. WARNING! Do not clean not the ﬁ lter with petrol. Hazardous! TIP! Use Husqvarna’s cleaning agent Active Cleaning no. 505 69 85-70. 505 69 85-70 Impregnate the ﬁ lter with air ﬁ lter oil.
Fuel system Tank venting Tank venting Check that the tank venting valve works Tank venting takes place through the fuel correctly. cap and needs to be functional for the engine to work. • Empty the fuel tank. • Remove the air ﬁ lter cover. •...
Fuel system Carburettor Carburettor Dismantling Dismantling Remove the carburettor cover and the air 1. Remove the carburettor cover and the ﬁ lter then blow clean around the carburet- air ﬁ lter. 2. Close the choke valve and blow off Dismantle the throttle cable and fuel any dirt around the carburettor.
Fuel system Tag bort de 4 skruvarna. Dismantle the fuel pump’s diaphragm and the valve housing. De är långa och håller ihop hela förgasa- ren. Lyft därefter bort bränslepumpens blåsa (A) och ventilhuset (B). Tag bort styrmembranet och inspektera det avseende materialskador och slitage på...
Fuel system Check the lever arm and needle valve for Check the wear to the lever arm partly wear. by the contact points against the control diaphragm and partly by the cut-outs for Replace damaged parts with new parts. the needle valve. Also check wear to the tip of the needle valve and the groove for the lever arm.
Fuel system Assembling the carburettor Assembling the carburettor Walbro WYL Clean and inspect all parts. Clean and inspect all parts. Worn or damaged parts are replaced Worn or damaged parts are replaced with with new ones. new ones. Pay attention to the following when the Pay attention to the following when the carburettor is assembled in the reverse carburettor is assembled in the reverse...
Fuel system Assembly Assembly Check the distance piece for cracks. Inspect the distance piece (A) for cracks that can cause starting problems and neg- A defective distance piece must be re- ative idling. Check also that the impulse placed. channel (B) is open and not completely or Make sure that the impulse channel is partly blocked with grease, for instance, or entirely open.
Fuel system Throttle handle Throttle handle Dismantle the throttle cable (incl. the ad- 1. Dismantle the entire throttle cable from justment screw from the carburettor). the carburettor (incl. the adjustment screw). Separate the short-circuit cables and remove the lockwasher that holds the han- 2.
Fuel system 8. Remove the throttle control (B), the throttle cable (C), the triangle link (D) and the stop switch (E). 9. Remove the screw (F) and detach and twist in the opposite direction the lock (G) that prevents handle rotation. Assemble the throttle handle in the re- verse order as set out for dismantling.
Centrifugal clutch The centrifugal clutch has the task of transferring the power from the engine to the cutting equipment’s drive axle. As the name implies, it works according to a centrifugal principle. This means the clutch’s friction shoes are thrown outwards towards the clutch drum at a certain engine speed.
Centrifugal clutch Dismantle the clutch shoes from the hub. Dismantle the clutch shoes from the hub using a small screwdriver or a pointed tool. Check for wear on the friction lining. Check the friction linings for wear. The thickness must not be less than 1.3 mm. Replace worn or damaged components.
Centrifugal clutch Remove the circlip and dismantle the ball Remove the circlip holding the ball bear- bearings. ings in place in the gear housing. Then heat the gear housing to approx. 110°C and tap the housing against a wooden block so that the ball bearing falls out of the bearing seating or use a suit- able mandrel.
Cutting deck Cutting deck Cutting deck Dismantling Dismantling Disconnect the throttle cable and sepa- Unhook the throttle cable from the carbu- rate the connections on the short-circuit rettor and separate the connections to the cables. short-circuit cable. Remove the screws holding the engine to Remove the 4 screws holding the engine the vibrational dampers.
Cutting deck Remove the crank rod (C), the sealing felt (D) and the cutting knives (E). Lift up the lower crank rod completely with sprocket and eccentric cam (F). This gives access to the screws (G) for dismantling the chain bar.
Cutting deck Remove the circlip and pull the crank rod Remove the circlip and pull the crank rod over the eccentric cam. over the eccentric cam. See chapter entitled “Centrifugal clutch” for information on the small gear wheel . Assembly Clean and inspect all components for 531 00 92-05 wear and damage.
Cylinder and piston Cylinder and piston Contents Dismantling __________________________________ 34 Cleaning, inspection ___________________________ 35 Analysis and actions __________________________ 36 Service tips _________________________________ 40 Wear tolerances _____________________________ 41 Assembly __________________________________ 41...
Cylinder and piston The cylinder and the piston are two of the components exposed to most strain in the engine. They must withstand, for example, high speeds, large temperature swings and high pressure. Moreover, they must be resistant to wear. Despite these tough working conditions, major piston and cylinder failure is relatively uncommon.
Cylinder and piston Remove the circlips from the gudgeon pin. Remove the circlips on the gudgeon pin using a small ﬂ at nosed pliers. Keep your thumb over the circlip to pre- vent it from ﬂ ying out. Dismantle the piston. Push the gudgeon pin from the piston using punch 505 38 17-05.
Blocked spark arrestor mesh in the Clean or replace the spark arrestor mesh. mufﬂ er. For the best results we recommend Husqvarna two-stroke oil or ready-mixed fuel that is specially developed for air-cooled two-stroke engines. Mixing ratio: 1:50 (2%). If Husqvarna two-stroke oil is not available another good quality two-stroke oil can be used.
Cylinder and piston Piston scoring caused by heavy carbon deposits Too heavy carbon depositing can cause damage similar to that caused by insufﬁ cient lubrication. However, the piston skirt has a darker colour caused by the hot combustion gases that are blown past the piston. This type of piston damage starts at the exhaust port where carbon deposits can be- come loose and get trapped between the piston and the cylinder wall.
Cylinder and piston The guide pin for the piston ring has been Deep, irregular grooves caused by a loose Irregular grooves on the piston’s inlet side pushed up through the top of piston. circlip. Shown here on the piston’s inlet side. caused by a broken roller retainer.
Cylinder and piston Cause: Action: • Faulty air ﬁ lter. Small dust particles Fit a ﬁ ner grade ﬁ lter. pass through the ﬁ lter. • The ﬁ lter is worn out due to too much Check the ﬁ lter carefully for holes and cleaning, whereby small holes have damage after cleaning.
Cylinder and piston Larger, harder particles that enter the engine cause serious damage to the underside of the piston skirt. Cause: Action: • Air ﬁ lter damaged or missing. Fit a new air ﬁ lter. • Parts from the carburettor or intake Regular service and inspection.
Cylinder and piston Wear tolerances Piston ring gap Piston ring groove Piston ring play Cylinder bore When the surface coating is Max. 1.0 mm with the piston Max. 1.6 mm. Clean the groove Max. 0.15 mm. Clean the groove worn and aluminium appears. ring inserted in the lower part of before checking the measure- before checking the measure-...
Cylinder and piston Inspect the distance piece for crack forma- tion or other damage that may result in leakage, which in turn can cause uneven idling and starting difﬁ culties. Check that the impulse channel (A) is open all the way through the gaskets and the heat protective plate to the cylinder.
Crankshaft and crankcase Crankshaft and crankcase Contents Dismantling ________________________________ 44 Inspecting the crankshaft ______________________ 45 Assembly _________________________________ 46...
Crankshaft and crankcase The task of the crankshaft is to transform the reciprocating motion of the piston to rotation. This requires a stable design withstanding immense pressure and rotational and bending strain, as well as high rotational speed. In addition the connecting rod is exposed to large acceleration and retardation forces as it moves between the top and bottom dead centres.
Crankshaft and crankcase Lift the crankshaft out of the crankcase Dismantle the ball-bearings from the half on the starter side (a special tool is crankcase halves. not required). Heat the crankcase halves to 120°C using a hot air gun. Knock the crankcase half against a woo- Knock the crankcase half against a woo- den block so that the ball-bearing falls out.
Crankshaft and crankcase Inspect the small end of the connecting Inspect the small end of the connecting rod. rod. If seizure marks or discolouration are found in the bearing track the crankshaft must be replaced. Check the crank bearing. Check the crank bearing. The connecting rod shall not have any radial play (up and down).
Crankshaft and crankcase Fit the crankshaft in the crankcase half on Fit the crankshaft in the crankcase half on the ﬂ ywheel side. Lubricate the stub axle the ﬂ ywheel side. with a few drops of oil and carefully slide the crankshaft into the bearing.