Husqvarna 131R Workshop Manual

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 Prepare and do servicing on the product 3.1 Assembly................................................................5 3.2 Function test...........................................................8 3.3 Servicing schedule...............................................10 4 Technical data 4.1 Technical data......................................................11 5 Servicing data 5.1 Service data for the model 967 84 31-xx and the model 967 84 30-xx..............................................14 6 Servicing tools 6.1 Servicing tools for 967 84 31-xx and 967 84 30-xx.......................................................................... 16 7 Function overview 7.1 Type plate/Product serial number........................ 18 7.2 Engine..................................................................18 7.3 Fuel...................................................................... 18 7.4 Cutting equipment................................................19 7.5 To sharpen grass cutters and grass blades.........20 8 Repair instructions 8.1 Product overview for repair instructions............... 21 8.2 To clean and examine the product parts..............21 8.3 Starter.................................................................. 22 8.4 Ignition system..................................................... 24 8.5 Handle and throttle trigger....................................28 8.6 Air filter.................................................................29 8.7 Fuel tank.............................................................. 30 8.8 Fuel filter.............................................................. 30 8.9 Carburetor............................................................31 8.10 Centrifugal clutch............................................... 36 8.11 Bevel gear..........................................................39 8.12 Cylinder and piston............................................ 41 8.13 Crankshaft and crankcase................................. 49 8.14 Muffler................................................................ 52 9 Troubleshooting 9.1 Troubleshooting................................................... 53 2 675 - 002 - 23.04.2018

This manual gives a full description of how to do maintenance and repair on the product. It also gives safety instructions that the personnel must obey. 1.2 Target group This manual is for personnel with a general knowledge of how to do repair and do servicing. All personnel that do repair or do servicing on the product must read and understand the manual. 1.3 Revisions Changes to the product can cause changes to the maintenance work and spare parts. Separate information is sent out for each change. Read the manual together with all received information about changes to maintenance and spare parts for the product. 1.4 Safety 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. 675 - 002 - 23.04.2018 Introduction - 3

Warnings, cautions and notes are used to point out specially important parts of the manual. 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. CAUTION: Used if there is a risk of damage to the product, other materials or the adjacent area if the instructions in the manual are not obeyed. Note: Used to give more information that is necessary in a given situation. 2.2 General safety instructions WARNING: Read the warning instructions that follow before you use the product. The service center that repairs the product must have safety devices that obey local regulations. Warnings and cautions are used to point out specially important parts of the workshop manual. 2.3 Special safety instructions • When you use compressed air, do not point the airflow in the direction of your body. Air can go into the blood circulation and kill you. • Use eye protection when you do work on springs that have tension. • Do not use accessories that are not approved by the manufacturer. Do not do changes that are not approved by the manufacturer. This can cause injury or death to the operator or other persons. • Always use original spare parts and accessories. • Use approved hearing protection. Noise from the product can result in permanent hearing loss. 2.4 Symbols on the product WARNING! This product is dangerous. Injury or death can occur to the operator or bystanders if the product is not used carefully and correctly. To prevent injury to the operator or bystanders, read and obey all safety instructions in the operator's manual. Please read the operator's manual carefully and make sure that you understand the instructions before use. Use a protective helmet in locations where objects can fall on you. Use approved hearing protection. Use approved eye protection. Use approved protective gloves. Use heavy-duty slip-resistant boots. The product can cause objects to eject, which can cause injury. Maximum speed of the output shaft. 50FT 15 m 50FT 15 m Keep a minimum of 15 m (50 ft) distance to persons and animals during operation of the product. Risk of blade thrust if the cutting equipment touches an object that it does not immediately cut. The product can cut off body parts. Keep a minimum of 15 m (50 ft) distance to persons and animals during operation of the product. Air purge bulb. The direction to close the choke. The direction to open the choke. Keep all parts of your body away from the hot surfaces. Noise emission to the environment refer to the European Community's Directive. The emission of the product is specified in the Technical data chapter and on the label. Note: Other symbols/decals on the product refer to certification requirements for other commercial areas. 4 - Safety 675 - 002 - 23.04.2018

3.1 Assembly 3.1.1 Introduction WARNING: Read and understand the safety chapter before you assemble the product. 3.1.2 To install the main body 1. Connect the engine (A) to the tube (B) with four screws (C). A B C 3.1.3 To install the handlebar and throttle 1. Install the handlebar in the handlebar clamp on the shaft. 2. Put on the harness and hang the product from the support hook. 3. Make a last adjustment to make sure the product is in a comfortable position when it hangs from the harness. 4. Tighten the screws. 3.1.4 To connect the throttle cable and stop switch wires 1. Remove the air filter cover. 2. Install the throttle cable (A) through the carburettor bracket (B). A B C 3. Turn the cable adjuster sleeve (C) into the carburettor bracket fully. 4. Put the slot fitting (D) on the carburettor. At this time, the recessed hole (E) for the cable lug (F) is away from the cable adjuster sleeve (C). G D E F 5. Rotate the carburettor throttle cam and move the throttle cable (A) through the slot in the slot fitting. 6. Make sure the cable lug (F) drops into the recessed hole. 7. Operate the throttle trigger some times to make sure that it operates correctly. 8. Adjust the cable adjuster sleeve (C). 675 - 002 - 23.04.2018 Prepare and do servicing on the product - 5

cam touches the throttle stop correctly. b) Make sure the cable position keeps 1-2 mm between cable lug (F) and slot fitting when the throttle trigger is fully pushed. 1-2mm 9. When the throttle cable (A) is adjusted correctly, tighten the locknut (G). 10. Connect the stop switch wires (H) with the connectors from the engine. H H 11. Install the air filter cover. 3.1.5 To install the blade guard, grass blade and grass cutter CAUTION: Only use the approved guard for the blades. See the operator's manual. CAUTION: Make sure that the guard extension is removed. 1. Attach the blade guard/cutting attachment guard (A) onto the shaft and tighten with the bolt (L). B L A C A 2. Install the drive disc (B) on the output shaft. 3. Turn the output shaft until one of the holes in the drive disc aligns with the related hole in the gear housing. 4. Put the locking pin (C) in the hole to lock the shaft. 5. Put the blade (D), support flange (G) and the support cup (F) on the output shaft. 6. Put the cup washer (F) on the output shaft with the not flat side against the blade. 7. Install the nut (E). Hold the shaft of the wrench near the blade guard as much as possible. To tighten the nut, you must turn the wrench in the opposite direction of rotation. Tighten the nut to a torque of 35-50 Nm (3.5-5 kpm). F A C B E G D Note: Left hand thread. 3.1.6 To install blades and trimmer heads WARNING: Only use the approved guard for the blades, see the operator's manual. A defective guard can cause injury. WARNING: If you operate the product with a grass blade, first install the correct handlebar, blade guard and harness. WARNING: If you do not install the the blades correctly, it can cause injury. 1. Make sure that the lifted section on the drive disc/ support flange engages correctly in the center hole of the blades. 2. Install the blades. 6 - Prepare and do servicing on the product 675 - 002 - 23.04.2018

the trimmer head 1. Attach the guard (A) to the shaft and tighten with the bolt (L). Make sure to use the correct guard for the correct trimmer head. H B M A M L L H B M L G 2. Attach the drive disc (B) to the output shaft. 3. Turn the output shaft until the hole in the drive disc aligns with the hole in the gear housing. 4. Put the locking pin in the hole to lock the shaft. Put "G" on the shaft. 5. Turn the trimmer head (H) counterclockwise. H 6. To disassemble, do the reverse procedure. 3.1.8 To install the transport guard 1. Install the blade in the transport guard (A). 2. Put the two fasteners (B) into the slots (C) to attach the transport guard. B A C 3.1.9 To install the 2-teeth blade in the guard 1. Install the blade in the transport guard. 3.1.10 To adjust the harness WARNING: Always attach this product to the harness correctly. If not, you cannot control the product safely and this can result in injury to you or others. Do not use a harness with a defective quick release. WARNING: Use the harness quick release function if you must release from the product and the harness in an emergency situation. 1. Put on the harness. 2. Adjust the harness for the best work position. 3. Adjust the side straps until the weight is equally applied across your shoulders. 675 - 002 - 23.04.2018 Prepare and do servicing on the product - 7

parallel to the ground. 5. Let the cutting attachment stay lightly on the ground. Adjust the harness clamp to balance the product correctly. 3.2 Function test 3.2.1 To examine before start 1. Examine the product for missing, damaged, loose or worn parts. 2. Examine the nuts, screws and bolts. 3. Examine the blades. 4. Examine the locknut. Make sure that the locknut has a minimum locking force of 1.5 Nm (1,1 ft lb). Torque the locknut to 35-50 Nm (26-36 ft lb). 5. Examine the air filter. 6. Examine the throttle trigger lockout and the throttle control. 7. Examine the stop switch. 8. Examine the product for fuel leaks. 3.2.2 To start a cold engine WARNING: Before you start the product, install the complete clutch cover and shaft. The loose clutch can cause injury. Use gloves. WARNING: Move the product away from the refuelling area and the power. Put it on a flat surface. Make sure that no objects touch the cutting attachment. WARNING: Make sure that no unauthorised persons are in the work area. Or it can cause a risk of dangerous injury. The safety distance is 15 m. 1. Put the stop switch to the start position. 2. Press the air purge ten times. 3. Move choke control to the choke position. 4. Hold the product to the ground. Pull out the cord slowly with your right hand until you feel some resistance. Pull the cord quickly and with force. Keep doing it until you hear the engine start. Note: Do not twist the starter rope around your hand. CAUTION: Do not pull all the starter rope out. Hold the starter rope handle when it is fully extended. Failure to obey these instructions can cause damage to the engine. 5. Set the choke control to the run position, then pull the start rope until the engine starts. 8 - Prepare and do servicing on the product 675 - 002 - 23.04.2018

for 60 seconds. WARNING: Do not touch the cover. It can burn your skin and cause electrical shock if the spark plug cap is damaged. Do not use a product with damaged spark plug cap. 3.2.3 To start a warm engine 1. Put the stop switch to the start position. 2. Press the air purge ten times. 3. Set the choke control to the run position, then pull the start rope until the engine starts. 3.2.4 To stop • Push the stop switch to stop the engine. 675 - 002 - 23.04.2018 Prepare and do servicing on the product - 9

The descriptions of the maintenance procedures are in the operator's manual. Maintenance task Before use After each use Every 10 hours Every 25 hours Clean the external surfaces. √ Clean the air filter. Replace if it is necessary. √ Make sure that the harness frame is not damaged. √ Make sure that the throttle trigger lock and the throttle functions correctly. √ Make sure that the handle and the handlebar functions correctly. √ Make sure that the stop switch functions correctly. √ Examine the guards. √ Make sure that the blade is sharp and not damaged. √ Make sure the blade is installed correctly in the center position. Examine the trimmer head. √ Make sure that the idle speed functions correctly. √ Examine the locknut. √ Do a check of fuel leaks. √ Examine the transport guard. √ Examine the starter rope handle and the starter rope. √ Make sure that the bevel gear grease is sufficient. √ Clean the external part and the adjacent areas of the carburetor. √ Clean the external part of the spark plug. √ Remove the spark plug and examine the electrode gap. Adjust the dis- tance or replace the spark plug. Install a correct spark plug to the supres- sor. √ Clean the cooling system. √ Examine the fuel filter. √ Examine the fuel hose. √ Examine all cables and connections. √ 10 - Prepare and do servicing on the product 675 - 002 - 23.04.2018

4.1 Technical data Model Cylinder displacement cm3/cubic inch Cylinder bore Ømm/Øinch Stroke mm/inch Max. power/rpm kW/hp / rpm 967 84 30-xx 967 84 32-xx 32,6/1.99 36/1.42 32/1.26 0.9/7500 967 84 31-xx 967 84 33-xx 32,6/1.99 36/1.42 32/1.26 0.9/7000 Model Compression ratio Spark plug Electrode gap mm/inch Ignition system 967 84 30-xx 967 84 32-xx 8.5:1 NGK BPMR7A 0.6/0.02 FENGLONG CDi 967 84 31-xx 967 84 33-xx 8.5:1 NGK BPMR7A 0.6/0.02 FENGLONG CDi Model Air gap mm/inch Pre-ignition angle max output/idle Air filter type Carburetor type 967 84 31-xx 967 84 30-xx 967 84 32-xx 0.34/0.01 27/22 Dry sponge RuiXing SK-C33E/SS 967 84 33-xx 0.34/0.01 27/22 Dry sponge RuiXing H167-04 675 - 002 - 23.04.2018 Technical data - 11

967 84 32-xx 7000 3000±300 76/3 4500±300 967 84 31-xx 967 84 33-xx 7000 3000±300 76/3 4500±300 Model Drive gear angle Bevel gear ratio Control disc drive mm/inch Shaft diameter Ømm/Øinch 967 84 31-xx 967 84 30-xx 30 14:19 25.4/1 28/1.10 967 84 32-xx 967 84 33-xx 30 14:19 25.4/1 26/1.02 KG LBS Model Drive axle diameter Ømm/Øinch Weight without fuel kg/lbs Volume fuel tank Litre/US. pint 967 84 31-xx 967 84 30-xx 8/0.31 8.4/18.5 0.9/1.90 967 84 32-xx 8/0.31 10.1/22.3 0.9/1.90 967 84 33-xx 8/0.31 10.5/23.2 1.1/2.32 12 - Technical data 675 - 002 - 23.04.2018

967 84 30-xx Vibration levels (ahv,eq) at handles, equipped with trimmer head, left/right m/s2 5,56/6,94 5,56/6,94 Vibration levels (ahv,eq) at handles, equipped with grass blade, left/right m/s2 4,59/4,34 4,59/4,34 Noise emissions2 Sound power level, guaranteed (LWA) dB(A) 115 115 Sound power level, measured - see footnote 2 dB(A) 111,9 111,9 Sound levels 3 Sound pressure level at operator's ear, equipped with grass blade dB(A) 92,4 92,4 Sound pressure level at operator's ear, equipped with trimmer head dB(A) 93,6 93,6 Product dimensions Weight without fuel, cutting attachment and harness kg 7,0 7,0 Fuel tank capacity cm3 900 900 1 Reported data for equivalent vibration level has a typical statistical dispersion (standard deviation) of 1.5 m/s2. 2 Noise emissions in the environment measured as sound power (LWA) in conformity with EC directive 2000/14/ EC. Reported sound power level for the machine has been measured with the original cutting attachment that gives the highest level. The difference between guaranteed and measured sound power is that the guaranteed sound power also includes dispersion in the measurement result and the variations between different machines of the same model according to Directive 2000/14/EC. 3 Reported data for equivalent sound pressure level for the machine has a typical statistical dispersion (standard deviation) of 2.5 dB (A). 675 - 002 - 23.04.2018 Technical data - 13

5.1 Service data for the model 967 84 31-xx and the model 967 84 30-xx ▲ ▲ 4 mm 4 - 6 Nm 13 mm 18 - 20 Nm 4 mm 6 - 8 Nm 4 mm 4 - 6 Nm 4 mm 6 - 8 Nm 3 - 5 Nm 0.6 ~ 1.2 Nm 4 mm 4 - 6 Nm 13 mm 18 - 20 Nm 17 mm 18 - 20 Nm 5 mm 6 - 8 Nm 5 mm 8 - 10 Nm 4 mm 6 - 8 Nm 4 mm 6 - 8 Nm 19 mm 18 - 20 Nm 4 mm 6 - 8 Nm 4 mm 3 - 5 Nm 4 mm 4 - 6 Nm ● 4 mm 3 - 5 Nm 5 mm 6 - 8 Nm 4 mm 3 - 5 Nm 4 mm 4 - 6 Nm 3 - 5 Nm 14 - Servicing data 675 - 002 - 23.04.2018

0.6 - 1 Nm 1.5 - 2.5Nm 0.6 - 1 Nm 5 mm 6 - 8 Nm 4 mm 3 - 5 Nm 19 mm 18 - 20 Nm 5 mm 3 - 5 Nm 5 mm 6 - 8 Nm 1.2 - 2 Nm 1 - 1.5 Nm 4 mm 1.5 - 2 Nm 5 mm 6 - 8 Nm 675 - 002 - 23.04.2018 Servicing data - 15

6.1 Servicing tools for 967 84 31-xx and 967 84 30-xx 11 9 3 12 13 14 10 1 2 4 5 6 7 8 15 16 16 - Servicing tools 675 - 002 - 23.04.2018

510 13 90-01 2 Piston stop Locking the piston 522 43 18-01 3 Test spark plug Checking the ignition spark 502 71 13-01 4 Ignition cable plier Repairing the ignition cable 502 50 06-01 5 Flywheel removal tool Removing the flywheel 502 51 49-02 6 Active cleaning Cleaning product 505 69 85-70 7 Air filter oil Air filter cleaning 531 00 60-76 8 Pressure vacuum tester Leakage testing 531 03 06-23 9 Hook for fuel filter Removing the fuel filter 502 50 83-01 10 Pin To lock the angle gear 502 02 61-02 11 Carburetor adjustment screwdriver Adjusting the carburetor settings 501 60 02-03 12 Tachometer Checking engine rpm 502 71 14-01 13 Grease Greasing the parts in the angle gear 503 97 64-01 14 Allen key 4 mm 502 50 18-01 14 Allen key 5 mm 502 50 64-01 15 Air gap tool 0,3 mm Adjusting ignition module 502 51 34-02 16 Drift Disassembling/assembling sealing ring 505 38 17-09 17 Piston pin rod Disassembling/assembling piston pin 505 38 17-05 18 Piston assembly kit Assembling the piston 502 50 70-01 19 Assembly fixture For brush cutters and trimmers 502 51 03-01 20 Circlip Pliers N/A 21 Pliers N/A 675 - 002 - 23.04.2018 Servicing tools - 17

7.1 Type plate/Product serial number The product serial number is given on the type plate. Supply the model name and the article number when you send an order for spare parts. 7.2 Engine 967 84 31-xx and 967 84 30-xx have engines with rotating carburetors. 7.3 Fuel 7.3.1 To use fuel CAUTION: This product has a two-cycle engine. Use a mixture of gasoline and two-cycle engine oil. Make sure to use the correct quantity of oil in the mixture. Incorrect ratio of gasoline and oil can cause damage to the engine. 7.3.2 Gasoline CAUTION: Do not use gasoline with an octane number less than 90 RON (87 AKI). This can cause damage to the product. CAUTION: Do not use gasoline with more than 10% ethanol concentration (E10). This can cause damage to the product. • Always use new unleaded gasoline with a minimum octane number of 90 RON (87 AKI) and with less than 10% ethanol concentration (E10). • Use gasoline with a higher octane number if you frequently use the product at continuously high engine speed. 7.3.3 Two-cycle engine oil • Use only the two-cycle engine oil of high quality, especially HUSQVARNA two-cycle oil. Use only the oil of an air cooled engine. • Mixture ratio 1:40 (2.5%). • Oil of low quality and high oil/fuel ratio can decrease the lifetime of catalytic converters. • Speak to your dealer when you select an oil. • If Husqvarna two-stroke oil is not available, you can use another two-stroke oil of good quality that is intended for air cooled engines. Contact your dealer when you select oil. • Do not use the two-stroke oil for water-cooled outboard engines. The two-stroke oil is sometimes referred to as outboard oil. Gasoline,litre Oil,litre 2.5%(1:40) 5 0,125 10 0,25 15 0,375 20 0,50 7.3.4 To make the fuel mixture Note: Always use a clean fuel container when you mix the fuel. Note: Do not make more than 30 days quantity of fuel mixture. 1. Add half of the gasoline quantity. 2. Add the full quantity of oil. 3. Shake the fuel mixture to mix the contents. 4. Add the remaining gasoline quantity. 5. Shake the fuel mixture to mix the contents. 6. Fill the fuel tank. 7.3.5 To add fuel WARNING: Do not smoke or put hot objects near fuel. Before you add fuel, stop the engine and let it cool for minutes. WARNING: When you add fuel, open the fuel tank cap slowly to release unwanted pressure. WARNING: After you add fuel, tighten the fuel tank cap carefully. Move the machine away from the refuelling area and the power before you start the engine. 18 - Function overview 675 - 002 - 23.04.2018

• Make sure that the area near the fuel tank cap is clean. Contamination in the tank can cause operating problems. • Shake the fuel container before you add the fuel mixture to the fuel tank. 7.4 Cutting equipment 7.4.1 Cutting equipment • Use the blades and grass knives to cut thick grass. • Use the trimmer head to cut grass. • An incorrectly sharpened or damaged blade increases the risk of accidents. Keep the teeth of the blade correctly sharpened. Obey the instructions and use the recommended file gauge. • Examine the cutting attachment for damage or cracks. Replace a damaged cutting attachment. • Only use cutting attachments with recommended guards, see the operator's manual. 7.4.2 Trimmer head WARNING: Always make sure the trimmer line is wound tightly and evenly around the drum to prevent harmful vibration. • Only use recommended trimmer heads and trimmer lines. • Only use recommended cutting attachments. • Smaller machines requires small trimmer heads and vice versa. • The length of the trimmer line is important. A longer trimmer line requires greater engine power than a shorter trimmer line of the same diameter. • Make sure that the cutter on the trimmer guard is intact. This cuts the trimmer line to the correct length. • Soak the trimmer line in water for a couple of days before use to increase the life length. 7.4.3 Grass blades and grass cutters • Use the product with an approved grass blade. Do not use a grass blade without proper installation of all required parts. Make sure that the installation is done correctly and that the proper parts are used. Inproper installation may cause the blade to fly off and seriously injure the operator or the bystanders. • Wear protective gloves when you handle or do maintenance on the blade. • Use head protection when you operate a product with a grass blade. • Grass blades and grass cutters are used to cut rough grass. • A grass blade can cause injury while it continues to spin after the engine is stopped or the throttle trigger is released. Make sure that the grass blade has completely stopped rotating before any maintenance. • Stop the engine before you do work on the cutting attachment. Make sure the cutting attachment fully stops. Disconnect the lead from the spark plug. • Only use an approved cutting attachment or a correctly sharpened blade. • Keep the teeth of the blade correctly sharpened. • Do not use a damaged cutting attachment. • Attach the transport guard to the grass blade when you transport or store the product. 7.4.4 Blade thrust • A blade thrust is a sudden movement of the product to the side, forward or rearward. A blade thrust occurs when the grass blade or saw blade hits an object that cannot be cut. In areas where it is not easy to see the material being cut the risk of blade thrust increases. 675 - 002 - 23.04.2018 Function overview - 19

product or the operator moves out of position. A blade that moves can hit bystanders and there is a risk of injuries. • If a blade is bent, has cracks, is broken or damaged, discard the blade. • Use a sharp blade. The risk of blade thrust increases when a blade is not sharp. 7.5 To sharpen grass cutters and grass blades 1. Sharpen grass cutters and grass blades with a single-cut flat file. 2. Sharpen all edges of the grass cutters and blades equally to keep the balance. 20 - Function overview 675 - 002 - 23.04.2018

8.1 Product overview for repair instructions 7 9 1 12 2 8 4 6 3 10 5 11 1. Starter 2. Ignition system 3. Air filter 4. Fuel tank 5. Fuel filter 6. Carburetor 7. Handle 8. Centrifugal clutch 9. Bevel gear 10. Cylinder and piston 11. Crankshaft and crankcase 12. Muffler 8.2 To clean and examine the product parts • Clean and examine all parts fully. You find more instructions in the chapter for each part if special tools or procedures are necessary. • Replace damaged or defective parts. • Always use original spare parts. 675 - 002 - 23.04.2018 Repair instructions - 21

WARNING: Use protective glasses to prevent injury to the eyes if the recoil spring ejects. 1. Remove the screw (A), the spark plug cap (B), the spark plug cable (C) and the spark plug. Remove the screw (D) from the cylinder cover (E). A B D C E 2. Remove the screws (F) and the cylinder cover. Remove the screws (G and H). Remove the starter (J), the bracket (I), the gasket (K) and the nuts (L). G F I J K L H 3. Pull out the starter rope approximately 30 cm. Slow the starter pulley with your thumb. Put the starter rope in the groove in the starter pulley. Let the starter pulley rotate rearward until the spring tension stops. WARNING: The recoil spring can cause injury to your thumb when the starter pulley rotates in reverse. 4. Remove the screw (A) and remove the pulley (B). Remove the torsion spring (C). Remove the starter pulley (D) to access the recoil spring (E). Carefully remove the recoil spring (E) from the starter housing (F). M N O P Q R WARNING: Be very careful when you remove the starter pulley. The recoil spring can eject and cause injury to you. 22 - Repair instructions 675 - 002 - 23.04.2018

housing 1. Put the recoil spring in the starter groove of the housing. 2. Push down the recoil spring with your thumb on the inner side of the starter housing. 3. Move your thumb around the edge of the starter housing and push down the recoil spring turn after turn. 8.3.3 To replace the starter rope in the starter pulley 1. Pull the starter rope through the hole in the starter pulley and tie a knot. 2. Make sure that the knot is as small as possible and enters the groove on the starter pulley. 3. Wind the cord 3 turns counterclockwise around the starter pulley. 4. Lubricate the recoil spring and the stub axle of the starter pulley with cold resistant grease or thin oil. 5. Put the starter rope through the opening in the starter housing and the opening in the bearing journal. 8.3.4 To assemble the starter 1. Put the starter pulley down into the starter housing. 2. Put the torsion spring in the starter pulley. 3. Put the pulley on the starter pulley and attach the screw. 4. Pull the starter rope through the starter rope handle. 5. Make a small knot on the starter rope and pull the knot into the handle. 6. Tighten the recoil spring. Pull out the starter rope fully and slow the starter pulley with your thumb. Lift the starter rope up out of the groove on the starter pulley. Then turn the starter pulley counterclockwise 4 revolutions. Pull out the starter rope fully and turn the starter pulley a minimum of a half revolution more. 675 - 002 - 23.04.2018 Repair instructions - 23

screws (H) to the starter housing (J) and crankcase. Attach screws (G) to the support plate and the bracket (I). Attach the nuts (L) to the screws (G) and tighten. Put the cylinder cover in the correct position and attach the screws (F) to the starter housing and cylinder cover. Tighten the screws to the correct torque. Refer to Service data for the model 967 84 31-xx and the model 967 84 30-xx on page 14. G F I J K L H 8. Attach the screw (D) to the cylinder cover (E). Attach the spark plug cable (C). Attach the spark plug cap (B) and the screw (A). Tighten all screws to the correct torque. Refer to Service data for the model 967 84 31-xx and the model 967 84 30-xx on page 14 A B D C E 8.3.5 To replace the drive 1. Remove the starter assembly as given in To disassemble the starter on page 22. 2. Use a piston stop to lock the axle. 3. Loosen the nut (A). Remove the drive and the spacer in the drive disc. A 4. Examine the drive. Clean the drive if it is dirty. Replace the drive if it is damaged. 5. Assemble in the opposite sequence to how it was disassembled. 8.4 Ignition system 8.4.1 To disassemble the ignition system 1. Loosen the screws and remove the shaft assembly. 2. Remove the spark plug cover and the spark plug. 3. Remove the cylinder cover. 4. Remove the air filter cover. 24 - Repair instructions 675 - 002 - 23.04.2018

6. Disconnect the cables. 7. Remove the 2 screws (A) and the 4 screws (B) and pull away the clutch drum assembly (C). Remove the 2 washers. A B C 8. Remove the 2 screws (D), the cables (E), the ignition module (F) and the 2 washers (G). D E F G 9. Remove the 2 screws (H) and the spacers that hold the centrifugal clutch. Lift off the clutch. Remove the 2 spacers between the flywheel and the centrifugal clutch. H H 10. Attach the puller on the flywheel. Hold the puller to loosen and remove the nut. 675 - 002 - 23.04.2018 Repair instructions - 25

center bolt and use the holding tool to prevent movement until the flywheel releases. 8.4.2 To assemble the ignition system 1. Make sure that the keyway in the flywheel and the keyway in the crankshaft are not damaged. Make sure that the key is not damaged. Attach the flywheel and the centrifugal cluth with the spacers and screws as shown in the illustration. Note: Turn the clutch until you can see the arrows that show the turning direction. 2. Assemble the cables (E) to the ignition module (F). Use the 2 screws (D) and the 2 washers (G) to assemble the ignition module on the frame. D E F G 3. Use a feeler gauge to make sure the distance between the ignition module and the flywheel is 0.3 mm. 4. Assemble the clutch drum and clutch drum cover. Attach the clutch drum assembly (C) with the 2 screws (A), the 4 screws (B) and the 2 washers. A B C 26 - Repair instructions 675 - 002 - 23.04.2018

6. Assemble the throttle wire and attach the cap. 7. Assemble the air filter cover, spark plug, cylinder cover and spark plug cover. 8. Attach the shaft. Tighten the screws to the correct torque. See Service data for the model 967 84 31-xx and the model 967 84 30-xx on page 14. 8.4.3 To examine the ignition spark 1. Disassemble the spark plug cup and the spark plug cover. 2. Remove the spark plug and clean it from particles with a steel brush. 3. Examine the spark plug. If the electrodes are worn more than 50%, replace the spark plug. Make sure that the electrode gap is 0.6 mm. Adjust the space with the side electrode. 4. Ground the spark plug on the cylinder and pull tightly on the start handle. 5. If no spark occurs, replace the spark plug with a test spark plug see Servicing tools on page 16. If a spark occurs, the spark plug is defective. Replace the spark plug. 675 - 002 - 23.04.2018 Repair instructions - 27

connection. Remove the spark plug cover and make sure that the ignition cable is not damaged. If it is necessary, remove a part of the cable to get sufficient connection at the connection coil. 7. Use pliers to make a new hole in the ignition cable to attach the connection coil. 8. Attach the ignition coil to the ignition cable and make sure that the wire is folded along the cable. Move the connection coil into the spark plug cover. If it is necessary, lubricate the hole in the spark plug cover. 9. If no spark occurs, examine the other cables for unsatisfactory connections, dirt, corrosion, cable breakage and damaged insulation. If no spark occurs, replace the ignition module. Note: Use an Ohmmeter to examine if a cable is defective. 8.5 Handle and throttle trigger 8.5.1 To disassemble the handle 1. Remove the 4 screws, the bolt and the nut. 2. Remove the handles halves from the rod. Make sure that the parts do not fall to the ground. 3. Remove the throttle trigger (A). Remove the throttle wire (B). Remove the spring (C). Remove the throttle lock (D). B A C D 4. Remove the stop switch. 28 - Repair instructions 675 - 002 - 23.04.2018

1. Connect the cables to the stop switch. Connect the stop switch to the handle. 2. Attach the throttle lock (D). Attach the spring (C). Attach the throttle wire (B). Attach the throttle trigger (A). B A C D 3. Put the shaft in the left handle half. Attach the right half with the 4 screws, the bolt and the nut. Make sure that you use the correct torque. Refer to Service data for the model 967 84 31-xx and the model 967 84 30-xx on page 14. . 8.6 Air filter 8.6.1 To disassemble the air filter 1. Turn the knob (A) to remove the air filter cover (B). 2. Remove the air filter plate (C). 3. Remove the air filter (D). 4. Remove the air filter holder (E), if it is dirty or damaged. B C D A E 8.6.2 To clean and examine the air filter CAUTION: Do not use gasoline to clean the air filter, it will damage the air filter. 1. Examine the air filter. If the air filter is damaged, replace it with a new air filter. 2. Clean the air filter with warm water and cleaning agent. Make sure to use the correct cleaning agent, see Servicing tools on page 16. Flush the air filter with warm water until it is free of cleaning agent. 3. Soak the air filter with oil. Put the air filter in a plastic bag and put about a tablespoon of oil into the bag. make sure to use the correct oil, see Servicing tools on page 16. Press the outside of the plastic bag to apply the oil equally in the air filter. 8.6.3 To assemble the air filter 1. Assemble in the opposite sequence to how it was disassembled. 675 - 002 - 23.04.2018 Repair instructions - 29

8.7.1 To do a fuel tank venting Fuel tank venting must be done correctly for the engine to operate satisfactorily. 1. Empty the fuel tank. 2. Remove the air filter cover. 3. Remove the transparent fuel hose from the carburetor. 4. Connect the fuel hose to a pressure tester. Refer to Servicing tools on page 16. 5. Examine the hose bushings in the fuel tank for leaks. 6. Put your thumb on the hole in the fuel tank cap. 7. Pump up a vacuum of 0.5 bar in the fuel tank. 8. Remove your thumb from the hole in the fuel tank cap. The pressure decreases to atmospheric pressure in less than 15 seconds. 8.7.2 To clean and examine the fuel tank 1. Disassemble the fuel tank cap for cleaning. Use a screwdriver to remove the housing (A) that contains the check valve (B) and cover (C). 2. Use compressed air to clean the filter (D) and the hole in the fuel tank cap (E). 3. Examine the check valve. a) Press the sides of the check valve to see a small space (G). If you can see the space when you do not press the sides of the check valve, the valve is damaged. b) Replace the check valve if it is damaged. 4. Assemble the fuel tank cap. Make sure the seal (F) is not damaged. E F C D E B G A 5. Attach the fuel tank cap to the fuel tank. 8.8 Fuel filter 8.8.1 To remove the fuel filter 1. Loosen the hose clamp (A). A 2. Pull out the filter through the opening in the fuel tank with a hook. Refer to Servicing tools on page 16. 30 - Repair instructions 675 - 002 - 23.04.2018

CAUTION: Always replace a damaged fuel filter. 1. Examine the fuel filter. If the fuel filter is dirty, clean it with a brush. 2. If the fuel filter cannot be cleaned, replace the fuel filter. 3. Examine the fuel hose for cracks and leaks. Replace the fuel hose if it is damaged. 8.8.3 To attach the fuel filter 1. Attach the fuel filter to the fuel hose. 2. Make sure that you put the fuel filter as high up into the fuel hose as possible. 3. Tighten the hose clamp. Make sure that the filter cannot move off the tube. 8.9 Carburetor 8.9.1 To disassemble the carburetor 1. Remove the air filter cover and the air filter. 2. Close the choke valve and blow dirt off the carburetor. 3. Disconnect the throttle cable. 4. Disconnect the fuel hoses from the carburetor and make a note of how they are connected. 5. Remove the carburetor screws and the air filter holder. 6. Push fuel through the carburetor with the bellows of the fuel pump. Fill all the pipes with fuel. This pushes out all the bubbles that cause blockages in the pipes. 7. Remove the 2 screws (A) and lift off the throttle mechanism. Loosen the valve stop screw (B). Make sure that the sealing ring on the connection flange is not damaged. A A B 8. Remove the 4 screws (A). Remove the bellows of the fuel pump (B), the valve housing (C) and the control diaphragm. A A A A B C 675 - 002 - 23.04.2018 Repair instructions - 31

Clean the valve housing and make sure that the channels are open. Carefully push the short sides of the check valve (D) together to make sure that the seals are not damaged. Replace the valve if the seals are damaged. D C 10. Carefully remove the pump diaphragm and its gasket. Examine the diaphragm for wear, where the illustration show (A). Hold the pump diaphragm up to the light to find holes in the material. Clean the fuel screen (B). Replace the fuel screen if it is damaged. Use a needle to remove the fuel screen. B A A 11. Loosen the screw (A) and remove the lever, the axle, the needle valve and the spring. Be careful to prevent that the spring ejects. A 12. Examine the lever arm and the needle valve for wear. a) Examine the connection points against the control diaphragm for wear. b) Examine the grooves for the needle valve for wear. c) Examine the top of the needle valve for wear. d) Examine the groove for the lever arm for wear. e) Replace damaged parts with new parts. 13. Push out the seat of the needle valve for replacement. Use a correct punch Ø 4.5 mm. A B Note: Replace the seat, needle valve and lever arm at the same time. The seat of the needle valve must be pressed in level with the carburetor housing. Use a vise with soft jaw guards to prevent damage to the seat of the needle valve. 32 - Repair instructions 675 - 002 - 23.04.2018

out for disassembling. Make sure that the lever arm is flush with the diaphragm housing. If the lever arm is set too high, too much fuel goes into the carburetor. If the lever arm is set too low, a too small quantity of fuel goes into the carburetor. 15. Replace the nozzle of the carburetor if it is damaged. Use a small screwdriver to remove the nozzle (A) and the small O-ring (B) from the carburetor housing. A B Note: Do not disassemble the plastic pipe in the valve housing. 675 - 002 - 23.04.2018 Repair instructions - 33

A D E F G H I B C A. Sealing ring B. Gasket C. Diaphragm D. Screen E. Fuel inlet F. Valve, inlet G. Gasket H. Diaphragm I. Pump 8.9.3 To assemble the carburetor See Overview of the carburetor on 967 84 31-xx and 967 84 30-xx on page 34 for an overview of how the parts of the carburetor connects. 1. Assemble the carburetor in the opposite sequence to how it was disassembled. Make sure that the sealing ring has its wide edge against the carburetor housing. Make sure that the screen is clean and not damaged. 2. Do a pressure test of the carburetor: a) Make sure that the carburetor is sealed. b) Connect a pressure tester to the fuel inlet on the carburetor. Refer to Servicing tools on page 16. c) Pump up the pressure to 0.5 bar. 34 - Repair instructions 675 - 002 - 23.04.2018

to find leaks. No leakage is permitted. 3. Examine the distance piece for cracks and damage that can result in leakage. Replace the distance piece if it is damaged. 4. Make sure that the sealing ring (A) is attached correctly on the carburetor before the carburetor is attached on the engine. The wide edge on the ring must be nearest to the carburetor housing. A 5. Connect the fuel hoses and make sure that they are attached correctly. Hold the air filter in position and put the carburetor screws through the air filter holder and carburetor. Put the carburetor gasket in position and attach the carburetor tightly to the distance piece with the screws. 675 - 002 - 23.04.2018 Repair instructions - 35

8.10.1 To disassemble the clutch 1. Loosen the screws and remove the shaft assembly. 2. Remove the 4 screws. Remove the clutch drum assembly. 3. Put a piston stop in the spark plug hole to prevent movement of the piston. 4. Remove the 2 screws that hold the centrifugal clutch. Remove the clutch. Remove the flat washers that are behind the clutch shoes. 8.10.2 To clean and examine the clutch 1. Remove the clutch parts and examine for damage. 2. Examine the spring and outer edge for wear and damage. The thickness of the outer edge must be minimum 1.0 mm at the most worn point. 3. Replace damaged parts. 36 - Repair instructions 675 - 002 - 23.04.2018

1. Connect the clutch shoes together with the spring. Attach the clutch and the washers on the flywheel. See the turn arrows on the clutch shoes. 2. Attach the clutch drum assembly. 3. Remove the piston stop. 4. Attach the shaft with the screws. 8.10.4 To disassemble the clutch drum 1. Loosen the screws and remove the shaft assembly. 2. Remove the 4 screws. Remove the clutch drum assembly. 675 - 002 - 23.04.2018 Repair instructions - 37

housing. Do not remove the screw (A). Use pliers to remove the large snap ring (C). Remove the bushing (D). Use pliers to remove the small snap ring (E). A B C D E 4. Remove the clutch drum (F). Use pliers to remove the large snap ring (G). Remove the bearing (H). F H G 8.10.5 To assemble the clutch drum 1. Attach the bearing (H). Attach the large snap ring (G). Attach the clutch drum (F). F H G 2. Attach the small snap ring (E). Attach the bushing (D). Attach the large snap ring (C). Attach the clamp (B) to the clutch drum housing. A B C D E 3. Attach the clutch drum assembly with the 4 screws. 38 - Repair instructions 675 - 002 - 23.04.2018

8.11 Bevel gear 8.11.1 To disassemble the bevel gear 1. Remove the trimmer head (A). Remove the support flange (Y). Put a rod through the hole (B) to lock the axle. Remove the protective plate (C). Remove the screw (D), the screws (E) and the bracket (F). Remove the screw (G) and the bracket (H). Remove the screw (I) and pull out the gear housing (J). D E F H G I A J B C Y 2. Remove the bushing (K). Remove the snap ring (L) with pliers. Remove the snap ring (M) with pliers. Remove the grease plug (N). K L N M 675 - 002 - 23.04.2018 Repair instructions - 39

increase the temperature of the angle gear to approximately 110°C - 140°C. Hit the gear housing against a wooden block. Disassemble the input shaft assembly (O). 4. Increase the temperature of the gear housing to approx. 140°C. Disassemble the bearing (T) on the output shaft. If it is necessary, hit the gear housing against a wooden block until the bearing falls out. Disassemble the cogwheel (V) and bearing (X) from the output shaft (U). If it is necessary to replace the bearings (R and Q), remove the snap ring (P) from the input shaft (S). U T R S O Q P V X P 8.11.2 To assemble the bevel gear 1. Put the cogwheel (V) on the output shaft (U). Attach the 2 bearings (T and X). Increase the temperature of the gear housing to approximately 140°C with a hot air gun. Put the output shaft into the gear housing (J). Make sure that the bearings are in their correct positions. If it is necessary, use a sufficient punch. U T V X 2. Make sure the output shaft is attached to the gear housing. Attach the bearings (R and Q) on the input shaft. Make sure that the snap ring (P) that holds the ball bearings in position is attached. Make sure that the gear housing is approximately 110°C. Q R S P 40 - Repair instructions 675 - 002 - 23.04.2018

with a pair of pliers or a sleeve. 4. Attach the snap ring (L) for the bearing on the output shaft. Attach the bushing (K) on the output shaft. Attach the grease plug (N). Attach the snap ring (M) for the bearings on the input shaft. Fill the gear with grease. K L N M 5. Attach the gear housing (J) on the shaft and tighten the screw (I). Attach the bracket (H) and tighten the screw (G). Attach the bracket (F) and tighten the screw (E). Tighten the screw (D). Attach the protective plate (C). Remove the rod from the hole (B) to unlock the axle. Attach the support flange (Y). Attach the trimmer head (A). D E F H G I A J B C Y 8.12 Cylinder and piston 8.12.1 To get access to the cylinder and piston 1. Remove the shaft. 2. Remove the spark plug cover and the spark plug. 3. Remove the cylinder cover. 4. Remove the starter. 5. Remove the muffler and heat shield. 6. Remove the air filter cover, the air filter and the air filter holder. 7. Remove the carburetor, the distance piece and the heat shield. 675 - 002 - 23.04.2018 Repair instructions - 41

1. Remove parts as given in To get access to the cylinder and piston on page 41 to get access to the cylinder and piston. 2. Loosen the 4 bolts. Pull the cylinder up. Make sure no dirt goes into the crankcase. Put a cloth on top of the crankcase opening. 3. Use a pointed tool to remove the wrist pin snap rings. Hold down the snap ring with your thumb to make sure the snap ring does not eject. 4. Push the wrist pin from the piston with a punch of the correct dimension. If the wrist pin is too tight, increase the temperature of the piston with a hot air gun. 8.12.3 To clean and examine the cylinder and piston 1. Remove carbon particles from the top of the piston, from the combustion chamber of the cylinder and from the exhaust port of the cylinder. CAUTION: Clean carefully to not cause damage to the soft metal parts. 2. Clean all the components with water. 3. Examine the components for damage and wear. a) Examine the piston and cylinder for damage and wear. Refer to Faults and causes on page 43. b) Examine the piston rings for wear and damage. Refer to Faults and causes on page 43. c) Examine the wrist pin. Replace the wrist pin if it is blue. Replace the piston and the wrist pin if the piston moves too easily. d) Examine the needle bearing. Replace the needle bearing if it has discoloration or damages. e) Examine the snap rings. Replace the snap rings if they have cracks or discoloration. f) Examine the distance piece for cracks and other damage. 42 - Repair instructions 675 - 002 - 23.04.2018

8.12.4.1 Piston damages 8 3 9 1 2 4 5 6 10 7 11 675 - 002 - 23.04.2018 Repair instructions - 43

ample 1 Cause Procedure 1 The piston has small to moderate score marks usually in front of the exhaust port. Very high temperature makes the piston ma- terial come off along the piston skirt and cylin- der bore. Usually the piston ring is not damaged and moves freely in the ring groove. There can al- so be scores on the inlet side of the piston. The carburetor is incorrectly adjusted. Examine and adjust the car- buretor. The engine speed is higher than the recommended max. speed. Incorrect oil mixture in the fuel. Change to a fuel with the correct oil mixture. Too low octane fuel. Change to a higher octane fuel. Item The piston is not sufficiently lubricated, ex- ample 2 Cause Procedure 2 A piston ring that is almost blocked or fully blocked in its groove does not seal against the cylinder wall. This results in intense tem- perature increases in the piston. There can also be scores along the piston skirt on the inlet and on the exhaust sides. Incorrect oil mixture in the fuel. Change to a fuel with the correct oil mixture. Too low octane fuel. Change to a higher octane fuel. Air leaks. Damaged fuel hose. Inlet gasket leaks. Damaged distance piece or inlet manifold. Replace the damaged parts. Air leakage in the engine body. Crankshaft seals leaks. Cylinder and crank- case gaskets leaks. Replace damaged gaskets and shaft seals. Unsatisfactory mainte- nance. Dirty cooling fins on the cylinder. Blocked air in- take on the starter. Clean the cooling fins and the air intake. Blocked spark arrester screen in the muffler. Clean or replace the spark arrester screen. Item Scores on the piston because of heavy car- bon contamination Cause Procedure 3 This piston damage starts at the exhaust port. Carbon particles loosen and stay between the piston and the cylinder wall. Typical for this piston damage is brown or black discoloration of the piston skirt. Incorrect type of two-stroke oil or gasoline. Replace the fuel. Incorrect oil mixture in the fuel. Change to a fuel with the correct oil mixture. The carburetor is incorrectly adjusted. Adjust the carburetor. 44 - Repair instructions 675 - 002 - 23.04.2018

Too high engine speed can cause damage to the piston rings, the snap ring on the wrist pin and the bearings. Too high engine speed can also loosen the guide pin for the piston ring. A too lean carburetor setting results in too high speed and a high piston temperature. If the piston tem- perature increases too much, the piston ring is blocked and does not go down sufficiently in its groove. The edges of the piston ring can then hit the top edge of the exhaust port and break and cause piston damage. A too high engine speed also causes damage to the piston ring and play in the piston ring groove, usually in front of the exhaust port. The wear can cause the piston ring to catch in the exhaust port and cause damage to the piston. 4 The figure shows the exhaust side damaged by a broken piston ring. The piston ring parts damage the top section and cause score marks. 5 A too high engine speed causes the ends of the piston ring to hit the guide pin again an again. This can push the pin through the top of the piston and cause damage to the cylinder. 6 A too high engine speed causes vibration to the snap rings of the wrist pin. The snap ring pulls out of its groove and the tension of the snap ring decreases. The snap ring becomes loose and causes damage to the piston. 7 Failure of the crankshaft bearing or on the connecting rod bearing is usually caused by a too high engine speed. This results in the overload to the bearing or that the bearing becomes too hot. Overload to the bearing can prevent rotation of the bearing rollers and break the roller or ball retainer. The broken mate- rial causes a blockage between the piston and cylinder wall and causes damage to the piston skirt. Un- wanted material can also move through the supply channels of the cylinder. This causes damage to the combustion chamber of the cylinder and to the top and sides of the piston. 675 - 002 - 23.04.2018 Repair instructions - 45

Cause Procedure Unsatisfactorily filtered air that moves through the carburetor and into the engine causes damage to the cylinder and piston. The increased wear is seen on the inlet side of the piston. The wear starts at the lower edge of the piston skirt. 8 Small score marks and a matt, gray surface from small dirt particles on the inlet side of the piston. Defective air filter. Small dirt particles move through the filter. Attach a new filter of correct type. The filter is worn out be- cause of too much cleaning and small holes show in the material. Examine the filter carefully for holes and damage after cleaning. Replace the filter if it is necessary. Incorrect filter maintenance, such as incorrect procedure or incorrect cleaning agent. Air filter material becomes loose and holes show. Clean more carefully and use the correct cleaning agent, for example warm soap water. Replace the fil- ter. Air filter incorrectly attach- ed. Attach the filter correctly. Air filter damaged or miss- ing. Attach a new air filter. 9 Inlet side. Dirt from particles on the top of the piston and in the piston ring groove. The pis- ton ring is held tightly in the groove. Piston material is worn off. The lower part of the pis- ton skirt is thinner on the inlet side than on the exhaust side. Defective air filter. Small dirt particles move through the filter. Attach a new filter of correct type. The filter is worn out be- cause of too much cleaning and small holes show in the material. Examine the filter carefully for holes and damage after cleaning. Replace the filter if it is necessary. Incorrect filter maintenance, such as incorrect procedure or incorrect cleaning agent. Air filter material becomes loose and holes show. Clean more carefully and use the correct cleaning agent, for example warm soap water. Replace the fil- ter. Air filter incorrectly attach- ed. Attach the filter correctly. Air filter damaged or miss- ing. Attach a new air filter. 10 Larger, softer particles that enter the engine cause damage to the piston skirt below the piston ring. Air filter incorrectly attach- ed. Attach the air filter correctly. Air filter damaged or miss- ing. Attach a new air filter. 11 Larger, harder particles that enter the engine cause damage to the bottom of the piston skirt. Air filter damaged or miss- ing. Attach a new air filter. Parts from the carburetor or inlet system have come loose and entered the en- gine. Do maintenance regularly. 46 - Repair instructions 675 - 002 - 23.04.2018

Procedure Broken cooling fins, damaged threads or broken bolts by the exhaust port. Repair the threads with a thread repair kit. Replace the cylinder if it cannot be repaired. Score marks in the cylinder bore, especially by the ex- haust port. Polish the damaged area with an emery cloth of fine grade to remove the coating of aluminum. Replace the piston and cylinder if the score marks are large. Surface layer in the cylinder bore worn out, especially at the top of the cylinder. Replace the cylinder and piston. The piston shows signs of seizure score marks. Carefully polish the damaged area with an emery cloth of fine grade. Before the piston is attached to the cylinder, the piston must be polished as above. Replace the cylin- der and piston if the score marks are large. The piston ring is burned in its groove. Carefully loosen the piston rings and clean the groove before attaching them. Carbon particles in the groove de- crease the heat supply between the piston and cylinder. Be careful with the lower edge of the piston ring groove. If this is damaged, or if there are carbon particles, the com- pression pressure can leak through. To examine the wear on the piston ring, put it in the lower part of the cylinder bore. Bolts much too tight in the metal material. Put an applicable punch on the bolt head and hit the punch hard with a hammer. If the bolt does not loosen, do the procedure again. 8.12.5 Wear tolerance 8.12.5.1 Cylinder bore Examine the cylinder bore. Replace the cylinder bore if the surface layer is worn and aluminum shows. 8.12.5.2 Piston ring space Measure the piston ring space. The space must not be larger than 1.0 mm with the piston ring in the lower part of the cylinder. Replace the cylinder bore if the space is more than 1.0 mm. 675 - 002 - 23.04.2018 Repair instructions - 47

ring play 1. Clean and measure the the piston ring groove (A). The groove must not be larger than 1.6 mm. Replace the piston if the groove is larger than 1.6 mm. 2. Clean the piston ring groove and measure the piston ring play (B). The piston ring play must not be larger than. 0.15 mm. Replace the piston ring if the piston ring play is larger than 0.15 mm. A B 8.12.6 To assemble the cylinder and piston 1. Lubricate the needle bearing of the wrist pin with some drops of engine oil. 2. Point the arrow on the top of the piston in the direction of the exhaust port. Push the wrist pin and attach the piston rings. Note: Put a cloth in the crankcase opening to make sure that the piston rings do not fall into the crankcase. Make sure that the piston rings are correctly attached in the grooves. 3. Make sure that the pulse channel in the cylinder is open. Put a new cylinder base gasket on the crankcase. Lubricate the piston and the large end bearing with some drops of engine oil. Use the piston ring compressor and carefully move the cylinder into position. CAUTION: Do not turn the cylinder. The piston rings break easily. 4. Tighten the 4 screws diagonally. 5. Assemble the distance piece and heat shield on the cylinder. 6. Assemble remaining parts in the opposite sequence as set out for disassembling. Refer to To disassemble the cylinder and piston on page 42 48 - Repair instructions 675 - 002 - 23.04.2018

8.13.1 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. 1. Remove the key for the flywheel. 2. Remove the 4 screws (A) from the crankcase cover (D). D A 3. Remove the crankcase cover (D). Remove the crankshaft (E) from the crankcase (G). Remove the crankcase gasket (F). D E F G 4. Use a hot air gun to increase the temperature of the crankcase and the crankcase cover to 110°C. Hit the crankcase and the crankcase cover against a wooden block to make the bearings fall out. 5. While the crankcase half is warm, use a hammer and an applicable punch to hit out the sealing rings. 675 - 002 - 23.04.2018 Repair instructions - 49

crankcase The crankshaft can not be repaired, it must be replaced if it is worn or damaged. 1. Examine the large end of the connecting rod. Replace the crankshaft if you see scratch marks, discoloration on the sides or damaged needle holders. 2. Examine the small end of the connecting rod. Replace the crankshaft if you see scratch marks or discoloration in the bearing track. 3. Examine the bearing. Make sure the connecting rod does not have radial play. Make sure the connecting rod have axial play. Axial play is necessary for lubrication of the bearing. 8.13.3 To assemble the crankshaft and crankcase 1. Attach the bearing. a) Put the bearing in the crankcase and the crankcase cover. b) Use a hot air gun to increase the temperature of the crankcase and crankcase cover to 110°C. c) Use a hammer and an applicable punch to hit the bearings into position. d) Make sure that the bearings is against the shoulder in the bearing seat. 2. Attach the sealing rings. a) Attach the sealing rings in the crankcase and the crankcase cover with an applicable punch. b) Turn the sealing rings so the abraded edge faces inwards. c) The sealing ring on the flywheel side must be 5 mm below the edge of the bearing seating. Make sure the sealing ring levels with the crankcase on the starter side. 3. Attach the crankshaft. a) Lubricate the stub axle with some oil and carefully move the crankshaft (E) into the bearing in the crankcase (G). b) Make sure that the 2 guide bushings (H) are in position in the crankcase. 50 - Repair instructions 675 - 002 - 23.04.2018

crankcase. Use grease to make sure the gasket stays in position. F E G H 4. Prepare the crankshaft. a) Lubricate the crankshaft journal with some drops of oil and move the crankcase cover (D) into position. b) Tighten the 4 screws (A) crosswise. Make sure that the crankshaft rotates easily. D A 5. Attach the piston and the flywheel. a) Assemble the piston on the connecting rod. Make sure that the arrow on the piston points in the direction of the exhaust port. b) Put the spacers between the piston and the needle bearing. c) Make sure to put wrist pin snap ring correctly in the slots. d) Put the flywheel key in position in the crankcase keyway. Make sure that the flat surface is parallel to the center line of the crankshaft. e) Attach the flywheel. 6. Attach and lubricate the cylinder. a) Put the cylinder base gasket (I) in the correct position. b) Put a piston assembly kit (J) below the piston to make sure the piston is stable. c) Lubricate the piston and piston rings (K) with some oil. d) Use the piston ring compressor (L) and carefully move the cylinder into position. e) Tighten the four screws (M), diagonally. I J K L M 7. Assemble the remaining parts in the opposite sequence to how they were disassembled. 675 - 002 - 23.04.2018 Repair instructions - 51

1. Remove the 2 screws (A), the washers (B) and the screw (F). 2. Remove the muffler cover (C), the muffler (D) and the heat shield (E). 3. Remove the screw (H) and the protective plate (G). A C D B E F G H 8.14.2 To clean and examine the muffler WARNING: Risk of burn injury or fire. Mufflers with catalytic converters become very hot during operation. WARNING: Risk of fire. The exhaust gases are hot and can contain sparks. 1. Clean all parts. Clean the spark arrester screen with a wire brush. 2. Examine the muffler for wear and damage. Replace the muffler if it is damaged. 3. Examine the spark arrester screen. Replace the spark arrester screen if it is damaged. 4. Examine the remaining parts. Replace worn or damaged parts with new ones. 5. Make sure that the muffler is correctly attached to the product. 8.14.3 To assemble the muffler 1. Attach the protective plate (G) with the screw (H). 2. Hold the heat shield (E) in position and attach the muffler (D) and the muffler cover (C). 3. Attach the screw (F), the washers (B) and the 2 screws (A). A C D B E F G H 52 - Repair instructions 675 - 002 - 23.04.2018

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 The control diaphragm is damaged The control diaphragm has a defective seal Blocked needle valve The needle valve is worn Object in the needle valve guide Idle speed (low speed) The engine does not operate on idle speed The stop screw for the throttle does not operate correctly Blocked fuel filter Blocked fuel hose Air in fuel pipes The carburetor is not attached correctly The lever arm of the needle valve does not operate correctly The idle speed is too low Defective heat insulation seal The lever arm of the needle valve is damaged The lever arm of the needle valve is too high The lever arm of the needle valve does not operate correctly The needle valve is worn Object in the needle valve guide 675 - 002 - 23.04.2018 Troubleshooting - 53

The idle speed does not become stable 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 carburetor is not attached correctly The lever arm of the needle valve does not operate correctly The needle valve spring is not attached correctly The control diaphragm is damaged The needle valve is worn Object in the needle valve guide The engine stops when idling 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 The spring of the needle valve is damaged The needle valve spring is not attached correctly The needle valve is worn Object in the needle valve guide 54 - Troubleshooting 675 - 002 - 23.04.2018

high speed Blocked fuel filter Blocked fuel hose Air in fuel pipes Incorrect/unsatisfactory fuel Vacuum pulse leakage Blocked vacuum pulse pipe Loose screws on the pump cover Defective pump diaphragm The needle valve is defective The carburetor is not attached correctly The lever arm of the needle valve is damaged The lever arm of the needle valve does not operate correctly The spring of the needle valve is damaged The needle valve spring is not attached correctly The control diaphragm is damaged The control diaphragm has a defective seal The needle valve is worn Object in the needle valve guide Increasing and decreasing speed The engine does not increase speed Blocked fuel filter Blocked fuel hose Air in fuel pipes Vacuum pulse leakage Blocked vacuum pulse pipe Loose screws on the pump cover Defective pump diaphragm The needle valve is defective The carburetor is not attached correctly The lever arm of the needle valve is damaged The lever arm of the needle valve is too low The lever arm of the needle valve does not operate correctly The needle valve spring is not attached correctly The control diaphragm is damaged Blocked needle valve The engine stops when decreas- ing speed Defective pump diaphragm The lever arm of the needle valve is too high The lever arm of the needle valve does not operate correctly The needle valve is worn Object in the needle valve guide Can not increase speed Defective heat insulation seal 675 - 002 - 23.04.2018 Troubleshooting - 55