1. Manuals
  2. Brands
  3. Husqvarna Manuals
  4. Brush Cutter
  5. 331RB
  6. Workshop manual

Husqvarna 331RB Workshop Manual

Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
Workshop manual
331RB
English
1281 - 001 -

Advertisement

Table of Contents
loading

Related Manuals for Husqvarna 331RB

Summary of Contents for Husqvarna 331RB

  • Page 1 Workshop manual 331RB English 1281 - 001 -...

  • Page 2: Table Of Contents

    Contents 1 Introduction 1.1 Document description..........3 1.2 Target group............3 1.3 Revisions..............3 1.4 Safety..............3 1.5 Servicing tools............3 2 Safety 2.1 Safety definitions............4 2.2 General safety instructions........4 2.3 Special safety instructions........4 2.4 Symbols on the product......... 4 3 Servicing schedule 4 Servicing data 4.1 Servicing data............

  • Page 3: Introduction

    WARNING: All personnel that repair or do servicing on the product must read and understand the safety instructions in this workshop manual. 1.5 Servicing tools The manual gives information about necessary servicing tools. Always use original tools from Husqvarna. 1281 - 001 - Introduction - 3...

  • Page 4: Safety

    2 Safety 2.1 Safety definitions Use a protective helmet in locations where objects can fall on you. Use approved Warnings, cautions and notes are used to point out hearing protection. Use approved eye specially important parts of the manual. protection. WARNING: Used if there is a risk of injury or death for the operator or bystanders if the instructions in the manual are not obeyed.

  • Page 5: Servicing Schedule

    3 Servicing schedule The descriptions of the maintenance procedures are in the operator's manual. Maintenance task After Every Every Before each hours hours Clean the external surfaces. √ Clean the air filter. Replace if it is necessary. √ Make sure that the harness frame is not damaged. √...

  • Page 6: Servicing Data

    4 Servicing data 4.1 Servicing data 3 - 4 Nm 4 mm 2 - 3 Nm 4 mm 3 - 5 Nm 18 - 20 Nm 19 mm 2 - 3 Nm 3 mm 4 mm 3 - 5 Nm 8 mm 6 - 8 Nm 4 mm...
  • Page 7 1.2 - 2 Nm 3 - 5 Nm 5 mm 1.2 - 2 Nm 6 - 8 Nm 5 mm 3 - 5 Nm 4 mm 1.2 - 2 Nm 1.5 - 2.5 Nm 4 mm 4 - 6 Nm 5 mm 18 - 20 Nm 19 mm...

  • Page 8: Servicing Tools

    5 Servicing tools 5.1 Servicing tools 8 - Servicing tools 1281 - 001 -...
  • Page 9 Item Description Use to Article number Driver Remove the starter pawl assembly 510 13 90-01 Piston stop Lock the piston 522 43 18-01 Ignition tester Examine the ignition spark 502 71 13-01 Ignition cable pliers Repair the ignition cable 502 50 06-01 Flywheel removal tool Remove the flywheel 502 51 49-02...

  • Page 10: Function Overview

    • Always use a fuel container with an antispill valve. • If Husqvarna two-stroke oil is not available, use a • If there is some fuel on the container, remove the two-stroke oil of good quality for air-cooled engines.

  • Page 11: Repair Instructions

    7 Repair instructions 7.1 Product overview for repair instructions 1. Starter 4. Carburetor 2. Muffler 5. Clutch drum cover and clutch drum 3. Air filter and air filter holder 6. Ignition module 1281 - 001 - Repair instructions - 11...

  • Page 12: To Clean And Examine The Product Parts

    7. Centrifugal clutch 5. Let the starter pulley rotate rearward until the spring tension stops. 8. Flywheel 9. Cylinder and piston 10. Crankcase and crankshaft 11. Fuel tank 12. Frame and harness 13. Handle 14. Gearbox 7.2 To clean and examine the product parts •...
  • Page 13 7.3.2 To replace the recoil spring in the starter 5. Put the starter rope through the opening in the starter housing and the opening in the bearing housing journal. To disassemble the 1. Disassemble the starter, refer to starter on page 12 . 7.3.4 To assemble the starter 2.
  • Page 14 4. Make a small knot on the starter rope and pull the 7. Tilt the starter slightly forward to make sure that the knot into the handle. starter is installed correctly on the cylinder cover and on the muffler. 7.3.5 To replace the starter pawl assembly To disassemble the 1.

  • Page 15: Muffler

    7.4 Muffler 7.5 Air filter 7.4.1 To remove and install the muffler 7.5.1 To remove and install the air filter 1. Remove the 3 screws and the muffler cover. 1. Turn the engine around its axle to get access to the air filter.

  • Page 16: Carburetor

    3. Soak the air filter with oil. Put the air filter in a plastic 12. Needle jet bag and put about a tablespoon of oil into the bag. 13. Idle adjustment screw Servicing tools make sure to use the correct oil, see 14.
  • Page 17 and down with the throttle valve and adjusts the fuel 7.6.3.2 Part throttle position flow. 7.6.3.3 High speed position The throttle valve has 3 different positions: • Idle position • Part throttle position • High speed position 7.6.3.1 Idle position 7.6.4 Gravity fuel supply The fuel tank is installed above the carburetor.
  • Page 18 operation. If the product is tilted too much, the fuel does not go into the carburetor. 18 - Repair instructions 1281 - 001 -...
  • Page 19 7.6.5 Overview of the carburetor 1. Top cap 10. Screw 2. Piston valve 11. Fuel drain screw 3. Needle valve 12. Float chamber housing 4. Idle adjustment screw 13. Carburetor float 5. Choke plate 14. Fuel jet 6. Washer 15. Lever arm 7.
  • Page 20 19. Choke lever screw 3. Disconnect the fuel hose from the carburetor. 20. O-ring 21. Spring 22. Fuel valve 23. Screws 24. Washers 25. Gasket 26. Adapter 27. Screws 7.6.6 To disassemble and assemble the carburetor CAUTION: Before you do maintenance on the engine, the fuel valve must be closed.
  • Page 21 5. Loosen the top cap (L). Remove the piston valve 7. Remove the fuel jet (U), the lever arm (V), the axle (N), the throttle wire (M) the spring (O) and the (X) and the needle valve (Y). needle valve (P). 8.
  • Page 22 7.6.7 To clean and examine the carburetor 3. To adjust the fuel flow for high speed: Replace the main nozzle. 1. Examine the wear to the lever arm and the wear of a) Use a smaller main nozzle to increase the fuel the needle valve.

  • Page 23: Ignition System

    7.7 Ignition system 3. Connect the ignition tester to the spark plug cap and ground the clip to the cylinder. 7.7.1 Introduction The engine has an electronic ignition system fully without moving parts. A defective component cannot be repaired, but must be replaced by a new component. If the engine does not fire, the ignition module can be damaged.
  • Page 24 3. Turn the spring to remove it from the cable. 6. Put the spring into the new hole. 7. Put the cable with the open spring into the other slot in the pliers. Close the pliers to bend the spring. 4.
  • Page 25 10. Use the pliers or a screwdriver to align the spring 5. Disconnect the throttle wire from the carburetor. with the hole in the spark plug cap. 6. Disconnect the cables. CAUTION: Be very careful to prevent damage to the spark plug cap. A damaged spark plug cap can cause an electrical shock.
  • Page 26 7. Remove the 3 screws (A) and the muffler cover (B). 11. Remove the screws, the washers, the cables and the ignition module. 12. Remove the 2 screws and the 2 washers that hold the centrifugal clutch. Remove the centrifugal clutch and the 2 washers between the flywheel and the centrifugal clutch.
  • Page 27 14. Hold the flywheel puller and loosen and remove the 3. Attach the flywheel and the centrifugal clutch with flywheel nut. the spacers and screws as shown in the illustration. 15. Attach the center unit to the flywheel puller. Hold the flywheel puller and use a wrench to tighten the Note: Turn the clutch until you can see the arrows center bolt until the flywheel releases.

  • Page 28: Centrifugal Clutch

    7.8 Centrifugal clutch 5. Use a feeler gauge to make sure that the distance between the ignition module and the flywheel is 0.3 -0.5 mm. 7.8.1 To remove the centrifugal clutch 1. Pull up the knob and remove the shaft. 2.

  • Page 29: Cylinder And Piston

    4. Remove the 2 screws that hold the centrifugal 7.8.2 To clean and examine the centrifugal clutch clutch. Remove the centrifugal clutch and the flat 1. Examine the spring and outer edge for wear and washers that are behind the clutch shoes. damage.
  • Page 30 6. Remove the air filter cover, the air filter and the air 6. Push the wrist pin from the piston with a punch of filter holder. the correct dimension. 7. Remove the carburetor, the distance piece and the heat shield. 7.9.2 To disassemble the cylinder and piston To get access to the 1.
  • Page 31 7.9.3 To clean the cylinder and piston • Make sure that the cylinder does not have score marks. CAUTION: Clean carefully. The soft aluminum parts are easily damaged. • Remove the carbon deposits from these parts: 7.9.5 To examine the piston •...
  • Page 32 • Put the piston ring in the cylinder and measure the 7.9.6 To assemble the cylinder and piston space with an air gap tool. The space must not be 1. Carefully put the piston ring on the piston. Make more than 1 mm. sure that you do not cause damage to the piston ring or the piston.

  • Page 33: Crankshaft And Crankcase

    7.10 Crankshaft and crankcase 5. Attach the G snap rings. 7.10.1 To disassemble the crankshaft and crankcase To get access to the crankshaft and crankcase, you must remove all components of the product. Refer to the manual section for each component for instructions. To disassemble the 1.
  • Page 34 9. Use a hot air gun to increase the temperature of the 7.10.2 To clean and examine the crankshaft and crankcase and the crankcase cover to 110°C. Hit the crankcase crankcase and the crankcase cover against a The crankshaft can not be repaired, it must be replaced wooden block to make the bearings fall out.
  • Page 35 a) Put the bearings in the crankcase and the a) Lubricate the stub axle of the crankshaft and the crankcase cover. large end of the connecting rod with some drops of two-stroke oil. Do not put oil on the threads. b) Use a hot air gun to increase the temperature of the crankcase and crankcase cover to 110°C.
  • Page 36 4. Lubricate the crankshaft journal with some drops of d) Attach the flywheel. two-stroke oil and move the crankcase cover into position. Do not put oil on the threads. 7. Attach and lubricate the cylinder. a) Put the cylinder base gasket (G) in the correct 5.

  • Page 37: Harness Frame

    8. Assemble the remaining parts in the opposite 4. Disconnect the fuel hose from the carburetor. sequence to how they were disassembled. 7.11 Harness frame 7.11.1 To remove the engine from the harness frame 1. Drain the fuel tank. 2. Pull up the knob and remove the shaft. 5.

  • Page 38: Handle And Throttle Trigger

    7.12 Handle and throttle trigger 7.11.2 To remove the fuel tank from the harness frame 7.12.1 To disassemble the handle 1. Drain the fuel tank. 1. Remove the 7 screws and 2 nuts. 2. Disconnect the fuel hose from the carburetor. 2.
  • Page 39 5. Remove the screw (I) and connection plate (J) that 7.12.2 To assemble the handle are attached below the stop switch (H). 1. Assemble the black cable (G) and red cable (F) in the cable retainer (K). Install the cable retainer on the left handle half.

  • Page 40: Gearbox

    7.13 Gearbox 4. Put the spring (C) on the throttle lock (D) and put it in the correct position on the handle half. Put the throttle trigger (A) on the handle, make sure the end 7.13.1 To remove the gearbox of the spring (B) is in the correct position in the 1.
  • Page 41 7.13.2 To disassemble the gearbox 6. Remove the input shaft assembly (O) from the gearbox. 1. Remove the gearbox from the product. Refer to remove the gearbox on page 40 . 2. Remove the bushing (K). 7. Increase the temperature of the gearbox to approximately 140°C.
  • Page 42 3. Put on protective gloves. Use a hot air gun to 9. Attach the snap ring (L) for the bearing on the output increase the temperature of the angle gear to shaft. approximately 140°C. 4. Put the output shaft into the gearbox. Make sure that the bearings are in their correct positions.

  • Page 43: Troubleshooting

    8 Troubleshooting 8.1 Troubleshooting Start The engine is not easy to start. The stop screw for the throttle does not operate correctly. Blocked fuel filter. Blocked fuel hose. Air in fuel pipes. Incorrect/unsatisfactory fuel. The needle valve is defective. The lever arm of the needle valve is damaged. The lever arm of the needle valve does not operate correctly.
  • Page 44 Idle speed (low speed) The engine stops at idle speed. The stop screw for the throttle does not operate correctly. Blocked fuel filter. Blocked fuel hose. Air in fuel pipes. The needle valve is defective. Defective heat insulation seal. The lever arm of the needle valve is too high. The lever arm of the needle valve does not operate correctly.
  • Page 45 Increase and decrease speed The engine stops when the speed is de- The lever arm of the needle valve is too high. creased. The lever arm of the needle valve does not operate correctly. The needle valve is worn. Object in the needle valve groove. The engine cannot increase speed.

  • Page 46: Technical Data

    9 Technical data 9.1 Technical data 331RB Engine Cylinder displacement, cm 32.6 Cylinder bore, mm Stroke, mm Idle speed, rpm 3000±300 Recommended max speed, rpm 10600 Max. engine output, according to ISO 8893, kW @ rpm 1 kW Ignition system...
  • Page 47 1281 - 001 - Technical data - 47...
  • Page 48 1141483-26 2019-09-27...

Table of Contents