The engine’s exhaust fumes are poisonous. Test run the in the Operator’s Manual. The assembly of other equipment engine outdoors. or accessories or spare parts not approved by Husqvarna can result in the failure to meet these safety demands and that Special tools the person carrying out assembly bears responsibility for this.
Starter Starter Contents Dismantling _______________________________________ 4 Assembly__________________________________________ 5 Assembling the starter with a start assistance spring ______ 5 Replacing the drive dogs _____________________________ 7...
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. 502 50 18-01 Dismantling Dismantling Model 333/335 Model 336 Remove the 4 screws and carefully Remove 2 of the screws holding the swing down the protective plate so far cover under the engine against the...
Starter Assembly Assembly Clean the component parts and assem- Clean component parts before ble in the reverse order as set out for assembling. dismantling. Replace the return spring/starter pulley and starter cord, if necessary. NOTE! The return spring and starter pulley are supplied pre-assembled and are fi tted in the starter housing as a single unit.
Starter Lubricate the spindle with a little grease Assemble the starter pulley. and fi t the starter pulley. Move the starter cord through the guide in the starter housing. Place the start assistance spring (A) in Position the start assistance spring in position.
Starter Tension the return spring. Tension the return spring. Pull out the starter cord completely and Check the spring tension. slow the starter pulley with your thumb. Lift the starter cord up out of the cut-out on the starter pulley. Now turn the starter pulley anticlock- wise, 6 turns.
Electrical system The engine is equipped with an electronic ignition system completely without moving parts. Consequently, 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 interpreted as weak and can be diffi cult to see while troubleshooting.
Electrical system When there is still no ignition spark, dismantle the short-circuit cable from the stop switch. Remove the connector by prying it up out of the throttle with a knife. Still no spark? Check the short-circuit cable with the help of an Ohmmeter.
Electrical system Still no spark? Still no spark? Check other cables and connections. Check other cables and connections for poor contacts (dirt, corrosion, cable breakage and damaged insulation). Make sure that the cables are correctly drawn and lie in the cable grooves. Do not forget to check the cables in the throttle too.
Electrical system Option A Option A Loosen the screw and slide the cable Loosen the screw (A) and slide the ca- holder (B) forwards. ble holder (B) forwards on the shaft. Remove the screws and slide the cover Remove the screws (C) and slide the (D) forwards.
Electrical system Dismantle the ignition module and the Remove the remaining screws (A) centrifugal clutch. holding the ignition module and both screws (B) that hold the centrifugal clutch. Lift off the clutch, both support washers and the ignition module. 502 50 18-01 Remove the nut holding the fl ywheel.
Electrical system Assemble the ignition module and ad- Assemble the ignition module. just the air gap to 0.3 mm. Adjust the air gap. It should be 0.3 mm between the permanent magnets in the fl ywheel and the ignition module. Tighten the screws and do not forget the ring cable lug under the outer screw.
Fuel system Tank venting Tank venting Tank venting takes place through the Check that the tank venting valve works fuel cap and needs to be functional for correctly. the engine to work. Replace the fuel cap if the valve is •...
Fuel system Clean the fi lter externally if it is not too If the fi lter is not too dirty, its surface can dirty. be cleaned with a brush. Replace the fi lter if required. Otherwise it must be replaced. Check the fuel hose for cracks and leaks.
Fuel system The carburettor’s design The carburettor’s design The carburettor can be divided into The carburettor can be divided into three diff erent functional units: the three diff erent functional units: the metering unit, the blending unit, and the metering unit, the blending unit, and the pump unit.
Fuel system Dismantling the carburettor Dismantling the carburettor Remove the control diaphragm and Unscrew the 2 bolts that hold the control check for damage. diaphragm cover and lift off the cover. Replace if required. Carefully remove the control diaphragm (A) and gasket (B). Check the diaphragm for holes and wear on the pin (C).
Fuel system Check the needle valve and the lever Check the needle valve for damage on arm for damage or wear. the tip and in the lever arm groove. Replace damaged components with Check the lever arm for damage to the new ones.
Fuel system Dismantle the main jet (A) and the plug Press out the main jet (A) with a suitable punch. (B). Remove the plug (B). Carefully drill a small hole (Ø 2 mm) in the plug and pry it up with a pointed object.
Fuel system Remove the valves and dampers. If these components are worn, idling is disrupted. Note how the choke valve (1), the throt- tle valve (2), the recoil springs (3) and (4) and the lever arm (notched by the arrow) (5) are fi tted. NOTE! Do not lose the ball and spring in the carburettor housing where the...
Fuel system • Mount the valves and dampers. Replace the fuel screen if it is damaged or cannot be cleaned. Place the pump diaphragm closest to the carburettor housing. Then the gasket and cover and the other components in reverse order of removal.
Fuel system Fit the jet needles and adjust their set- ting. Model H 0.75 2.0 (EL-36D) 1.0 (EL-36D) 2.0 (EL-36D) 1.0 (EL-36D) 0.75 2.0 (EL-36D) 1.0 (EL-36D) NOTE! The H-needle is a little shorter than the L-needle. Press the stop plugs (A) in position using tool 504 62 29-01.
Fuel system The holder for the air fi lter contains a 333/335 device that opens two air ducts in the cylinder during acceleration. A rotary valve connected to the throttle valve lever opens the air supply in proportion to the acceleration. The device has the task of preventing uncombusted fuel/air mixture from going directly out into the exhaust channel.
Fuel system Assembly 1. Fit the rubber connection (A) on the cylinder. Lubricate with silicone spray or washing-up liquid so it slides easily into the holes. NOTE! Do not lubricate the rubber connection with oil as this can cause the rubber to swell. 2.
Fuel system Pay attention when the halves are sepa- rated so that both rubber elements (1), one on each side, are not lost. Remove the short-circuit cable from the switch (2). Lift up the throttle cable (3) from the channel and unhook it from the throttle (4).
Fuel system Disassemble the throttle control (A), the lock to prevent accidental throttle opera- tion (B), the start throttle lock (C) and the throttle stop (D) in order to check if replacement is necessary. The stop switch can also be disassemb- led now, and replaced if necessary.
Fuel system Carburettor settings 333/335 WARNING! When testing the engine in connection with carburettor adjustment, the clutch and clutch cover must be mounted together with the shaft and angle gear under all circumstances Otherwise there is a risk of the clutch becoming loose resulting in serious personal injury.
Fuel system Fine adjustment NOTE! Fine adjustment of the carburettor should be carried out after If the cutting equipment rotates while idling the the engine has been “run-in”. It is important that the air fi lter is T-screw should be turned anticlockwise until it stops. clean and that the carburettor cover is fi tted when adjusting the carburettor.
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 centrifugal clutch. Remove both screws (F) holding the centrifugal clutch. Lift off the clutch and both support washers. 502 50 18-01 Twist apart the clutch and inspect the Twist apart the clutch. diff erent parts with regard to wear or Inspect the diff erent parts with regard to damage.
Centrifugal clutch Remove the 3 screws and lift the con- 333/335 nection sleeve (B) off of the clutch housing. Dismantle the vibration element (C) Press the vibration element (C) together together with the clamping sleeve for with the clamping sleeve out from the 333/335 possible replacement.
Centrifugal clutch Check the inside diameter of the clutch Check the clutch drum for wear. drum. If it exceeds 64.0 mm it should be The diameter must not exceed 64.0 replaced. mm. If this is the case replace the clutch drum.
Angle gear The angle gear has two purposes: The fi rst is to gear down the engine’s high speed to better suit the lower speed a saw blade or trimmer re- quires to work effi ciently. Secondly, the angle gear contributes towards the operator’s working stance so that it is comfortable and at the same time effi cient.
Angle gear Dismantle the bearings from the output Dismantle the bearings from the output and input axles. and input axles with the help of a small bearing puller. TIP! Hold the bearing puller in a vice so that it gains a better grip around the bearing. Assembly Clean all component parts and replace if damaged or worn.
Angle gear Model 333/335 333/335 On models with a two-piece shaft, the (model L och RJ) guide becomes accessible once the shaft has been split (see chapter 3). Dismantle the sleeve (A) and pull out the guide (B) by pulling the drive axle. Model 336 Loosen the turn handle (A) and both screws (B).
Cylinder and piston Cylinder and piston Contents Dismantling ____________________________________ 46 Cleaning, inspection ______________________________ 47 Analysis and actions ______________________________ 47 Service tips _____________________________________ 52 Wear tolerances _________________________________ 52 Assembly_______________________________________ 53...
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 Cleaning, inspection After dismantling, clean the individual components: 1. Scrape carbon deposits from the top of the piston. 2. Scrape carbon deposits from the cylinder’s combustion chamber. 3. Scrape carbon deposits from the cylinder’s exhaust port. NOTE! Scrape carefully with not too sharp a tool so as not to damage the soft aluminium parts.
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. Mixing ratio: 1:33 (3%) or 1:25 (4%).
Cylinder and piston Piston damage caused by a too high engine speed. Typical damage associated with a too high engine speed includes broken piston rings, broken circlip on the gudgeon pin, faulty bearings or that the guide pin for the piston ring has become loose.
Cylinder and piston Foreign objects Everything other than clean air and pure fuel that enters the engine’s inlet port cau- ses some type of abnormal wear or damage to the cylinder and piston. This type of increased wear shows on the piston’s inlet side starting at the lower edge of the piston skirt.
Cylinder and piston Larger, softer particles that penetrate into the engine cause damage to the piston skirt under the piston ring as the illustration shows. Cause: Action: • Air fi lter incorrectly fi tted. Fit the air fi lter correctly. •...
Cylinder and piston Service tips Defect: Action: Broken cooling fi ns, damaged threads or sheared bolts by In severe cases – replace the cylinder. the exhaust port. Repair the threads using Heli-Coil. Seizure marks in the cylinder bore (especially by the ex- Polish the damaged area using a fi ne grade emery cloth so haust port).
Cylinder and piston Assembly Assembly Clean the crankcase. Clean the crankcase. Fit the piston on the connecting rod Assemble the piston on the connecting so that the arrow on the piston points rod. towards the exhaust port. Lubricate the gudgeon pin’s needle bearing with a few drops of engine oil.
Cylinder and piston Do a test of the gaskets of the crankcase and cylinder 1. Assemble the distance piece/heat shield with 1 screw (A). 2. Attach the seal intake with 2 screws (B). 3. Attach the sealing plugs (C) to the distance piece/heat shield.
Crankshaft and crankcase Crankshaft and crankcase Contents Dismantling ____________________________________ 56 Inspecting the crankshaft _________________________ 58 Assembly ______________________________________ 59...
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 bet- ween the top and bottom dead centres.
Crankshaft and crankcase Lift off the plastic piece that separates Lift off the plastic piece that separates the wide fl ush channel in the crankcase. the wide fl ush channel in the crankcase. Dismantle the ball-bearings from the Dismantle the ball-bearings from the crankcase halves.
Crankshaft and crankcase Inspecting the crankshaft The crankshaft cannot be reconditioned but must be replaced if it is worn or damaged. Inspect the large end of the connecting rod. If seizure marks, discolouration on the sides or damaged needle holders are found the crankshaft must be repla- ced.
Crankshaft and crankcase Assembly Assembly Mount the bearings in the crankcase Mount the bearings in the crankcase halves. halves. Heat the crankcase halves to approx. 110°C using a hot air gun. Put the ball- bearings in position. Use a suitable punch and hammer, if needed.
Crankshaft and crankcase Assemble the piston on the connecting Assemble the piston. rod. Attach the fl ywheel. Check that the piston is turned so the arrow points towards the exhaust port. Make sure that the gudgeon pin circlips are seated correctly in the slots. Attach the fl ywheel.
List of tools Tools Contents Starter _______________________________________62 Electrical system _______________________________62 Fuel system ___________________________________62 Centrifugal clutch ______________________________62 Angle gear ___________________________________63 Cylinder and piston ____________________________63 Crankshaft and crankcase _______________________63 Workshop equipment __________________________63...