Husqvarna 570 AT Workshop Manual Download | Manualshive

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CARBURETTOR

English – 31

WARNING!.

The.fuel.used.in.the.chainsaw.has.the.

following.hazardous.properties:

1..The.fluid.and.its.fumes.are.poisonous.

2..Can.cause.skin.irritation.

3..Is.highly.inflammable.

Carburettor

!

Description

The drawings accompanying this description do not

correspond with the carburettor on the chainsaw. They

only show the principle for the design and function.

Design

The carburettor is based on three sub-systems:

• The metering unit, A in fig. 1.

• The mixing venturi, B in fig. 2.

• The pump unit, C in fig. 3.

The jets and the fuel’s control functions are located in

the metering unit (A). Here the correct quantity of fuel is

adjusted for the actual speed and power output.

The mixing venturi (B) houses the choke, throttle valve

and diffuser jets. Here air is mixed with the fuel to give a

fuel/air mixture that can be ignited by the ignition spark.

In the pump unit (C), fuel is pumped from the fuel tank

to the metering unit. One side of the pump diaphragm is

connected to the crankcase and pulses in time with the

pressure changes in the crankcase. The other side of the

diaphragm pumps the fuel.

Fig. 2

Fig. 3

Fig. 1

B

C

A

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Summary of Contents for 570 AT

Page 1: ...English 570 576 XP G 570 AT 576 XP G AT Workshop manual ...

Page 2: ...ical data 6 Service tools 8 Service data 10 Safety equipment 12 Starter 18 Electrical system 20 Centrifugal clutch 26 Lubrication system 28 Carburettor 30 Tank unit 41 Anti vibration system 43 Piston and cylinder 44 Crankcase and crankshaft 50 Troubleshooting 55 ...

Page 3: ...ion This means that in time this Workshop manual will become out of date In order to prevent this the Manual should be read together with all service information issued concerning the chainsaw in question Layout This Workshop Manual can be used in two different ways For the repair of a particular system on the chainsaw Dismantling and Assembly of the entire chainsaw Repair of a particular system W...

Page 4: ...ing Do not use the saw until it has been adjusted so that the chain remains still when idling After test running do not touch the muffler until it has cooled Risk of burn injuries Insufficient lubrication of the chain can result in the chain breaking whichcancauseseriousorevenlife threatening injury Ensure that the spring in the starter does not fly out and cause personal injury If the spring tens...

Page 5: ...Symbols in this Workshop Manual This symbol indicates a risk of personal injury if instructions are not followed Choke Switch for hand grip heater Fuel filler Stop button Screw to adjust chain lubrication Saw chain oil filler Chain brake Decompression valve Use protective gloves Use protective goggles ...

Page 6: ...d Chain pitch Drive link cm inch mm inch mm inch m s 570 15 28 38 71 28 5 9 52 3 8 1 5 0 058 576 XP G 15 28 38 71 28 5 9 52 3 8 1 5 0 058 Spark plug gap Ignition system Air gap Carburettor type mm inch mm inch 570 0 5 0 02 SEM CD COT 0 30 0 012 Zama C1M EL28 EL50 576 XP G 0 5 0 02 SEM CD COT 0 30 0 012 Zama C1M EL28 EL50 570 AT 0 5 0 02 SEM CD COT 0 30 0 012 Zama C1M EL40 576 XPG AT 0 5 0 02 SEM C...

Page 7: ...Y Fuel tank volume Oil pump capacity Oil tank volume Automatic oil pump Litres US pint cm3 min Litres US pint 570 0 70 1 5 5 22 0 40 0 8 Yes 576 XP G 0 70 1 5 5 22 0 40 0 8 Yes Weight without Weight with Hand grip heater Electric carburettor bar and chain bar and chain heater kg lbs kg lbs 570 6 6 14 6 18 8 1 17 8 576 XP 6 6 14 6 18 8 2 18 0 576 XPG 6 8 15 0 18 8 4 18 4 Yes Yes rpm OIL ...

Page 8: ...8 English SERVICE TOOLS 11 9 3 12 13 10 1 2a 4 5 6 7 8 2b ...

Page 9: ... Checking the ignition module 502 71 13 01 14 Clutch tool Dismantling of clutch 502 52 22 01 15 Assembly pliers Assembly of spark plug cap 502 50 06 01 16 Hook for fuel filter Removing fuel filter 502 50 83 01 17 Assembly fixture Assembling chain saw 502 51 02 01 18 Hexagonal screwdriver For M4 screws 502 50 86 01 18 Hexagonal screwdriver For M5 screws 502 50 87 01 18 Hexagonal screwdriver For M6 ...

Page 10: ...rts screwed on indicate the tightening torque Nm 9Nm 4mm 13Nm 13mm 20Nm 19mm 20Nm 5mm 15Nm 5mm 15Nm 13mm 9Nm 4mm 9Nm 4mm 4 5Nm 4mm 8 5Nm 4mm 1 5Nm 1 5Nm 3 5Nm 4mm 11Nm 5mm 20Nm 5 5Nm 4mm Lubricate with two stroke oil Lubricate with chain oil Lubricate with grease ...

Page 11: ...SERVICE DATA English 11 2Nm 4mm 2Nm 4mm 5Nm 4mm 5Nm 4mm 9Nm 4mm 5Nm 4mm 5Nm 4mm 4Nm 2 5Nm 4mm 23Nm 13mm 11Nm 5mm 4Nm 4mm 4 5Nm 4mm 14Nm 4mm 9Nm 4mm 7Nm 4mm 8Nm 4mm 2Nm 4mm 2Nm 4mm ...

Page 12: ... Remove the four screws B and the cover over the chain brake mechanism See fig 1 A B C E D F Fig 5 A B 5 Removethepressurespringbyfreeingthebackend with a screw driver See fig 2 6 Remove the locking ring A with washer B and lift up the clutch drum E with needle bearing D and chaindrive sprocket C See fig 3 7 Remove the hand guard two screws A Note the sleeve on the starter side See fig 4 8 Remove ...

Page 13: ... with spring C See fig 5 6 Fit the cover over the chain brake mechanism Four bolts B Tighten the bolts to 4 Nm See fig 1 7 Fit the chain guide plate with bolt A See fig 1 8 Fit the hand guard with the sleeve on the starter side See fig 8 9 Push back the hand guard so that the chain brake is in the off position 10 Check that the brake strap is correctly positioned in the recess in the crankcase See...

Page 14: ... surface is given in the table below 2 Let go of the front hand grip and let the chainsaw pivot round on the rear hand grip 3 When the bar hits the surface the chain brake should cut in Function check L L Fig 10 L H Fig 11 Chain catcher There are two types of types of mountings for the chain catcher fitted on the spike bumper or the crankcase Dismantle the chain and bar See Operator s Manual Inspe...

Page 15: ...bly 1 Clean the contact surfaces to the gasket cooling plate and cylinder 2 If the saw is fitted with a spark arrester refit it See fig 12 3 Fit the cooling plate gasket and muffler to the cylinder Tighten the two M6 bolts to the cylinder to 14 Nm Tighten the four M5 bolts to 10 Nm Muffler Stop switch Dismantling The stop switch is in the off position when the switch is pressed down and in the on ...

Page 16: ...nd grip insert See fig 16 Remove the handle insert A Remove the guide pin for the throttle B and throttle lock C using a punch See fig 17 Press apart with a screwdriver or the like the throttle lock control and take out the throttle lock from the recess in the hand grip See fig 18 Now remove the spring Fig 18 Fig 16 Fig 17 A B C A Fig 15 ...

Page 17: ...ubricate all guide pins and joint surfaces using light oil 2 Fit the throttle cable and lever A Fit the throttle lever C with pivot B See fig 20 3 Fit the spring in the recess in the throttle lock D Hold the spring in place and locate the throttle lock in the recess in the hand grip 4 Fit the throttle lock pivot B with the help of a driver See fig 20 5 Fit the hand grip insert with a screw when th...

Page 18: ...act spring back towards the centre and move freely Fig 1 Fig 2 Fig 3 4 Removethecentralbolt C andtakeoutthewasher and starter pulley D See fig 3 5 If the starter cord is to be replaced cut it off pull out the ends from the handle and starter pulley with pointed pliers 6 If the spring is to be replaced remove the screws E and the spring cassette F A B E F D C 1 Remove the four bolts holding the sta...

Page 19: ...se the starter pulley bearing and spring and fit thepulleyonthespindle Turngentlybackwardsand forwards until the spring catches on the stop in the housing 5 Fit the washer and bolt C See fig 3 Tighten the bolt to 4 Nm 6 Pull out the cord through its hole in the housing and fit the handle and secure it with a double knot See fig 5 7 Wind the cord onto the starter pulley and rotate the pulleyclockwi...

Page 20: ...park plug and fit the piston stop in spark plug hole See fig 2 7 Release the flywheel nut Unscrew the nut until it comes level with the outer end of the shaft thread See fig 3 8 Fit the flywheel puller Tighten down the two M5x25 bolts approx 10 turns Exercise care on saws with generators which can be damaged if the screws aretightenedtoodeep Tightenthecentrebolt while preventing rotation with the ...

Page 21: ... comes opposite the ignition module See fig 8 Fig 7 Fig 5 Fig 6 35Nm A Fig 8 7 Insert the feeler gauge Air Gap Tool 0 3 mm between the ignition module and the flywheel magnet The clearance only applies to the two lower pegs on the ignition module See fig 8 8 Push the ignition module against the flywheel and tighten the bolts D to 4 Nm See fig 8 9 Fit the cable guide and press on the ignition cable...

Page 22: ...eating element Measure the resistance in the front hand grip element between points C and B See fig 9 The ohmmeter should show 3 4 ohms If the value is higher replace the hand grip Generator Measure the resistance in the generator between the points A and E See fig 9 The ohmmeter should show 0 5 ohms If the value is higher replace the generator Switch Release one of the connections to the switch a...

Page 23: ...trical system for models with AutoTune differ from models without AutoTune The yellow short circuit wire A from the ignition module is connected to the stop switch The red wire A from the generator is connected to the carburettor AutoTune See figure 9b Fig 9b ...

Page 24: ...er element D and upper AV spring B Remove the bolt on the front AV element D See fig 10 3 Dismantle the screw on the heater switch A See fig 10 4 Dismantle the throttle cable A impulse hose B fuel hose C earth cable D and E See fig 11 5 Dismantle the sleeve on the carburettor adjustment short circuit cables F and H Loosen the cable I on the carburettor heater See fig 11 Fig 11 Fig 10 I G H F C D B...

Page 25: ...antle the cables A and B on the heater switch Loosen connection C See fig 12 7 Loosen the cable fastening on the tank See fig 13 8 Dismantle the screws A on the generator See fig 14 Replacing the heating element in the tank unit 1 Remove the rear hand grip insert A See fig 15 2 Remove the cable connections C and B See fig 15 3 Fit the heating element and cable connections Fig 15 A C B B C A A ...

Page 26: ... Fig 16 Fig 18 Fig 17 2 Remove the five bolts A B and C which hold the front hand grip See fig 17 3 Fit the new front hand grip by screwing in the five bolts A B and C Tighten the bolts to 4 Nm See fig 17 4 Connect the two cables A and B See fig 18 5 Fit the earth cable A See fig 16 A 2 x A B C A B ...

Page 27: ... with needle bearing D and chain drive sprocket E See fig 2 4 Remove the spark plug and fit the piston stop Remove the clutch with the clutch tool Note Left hand thread Screw in the direction of the arrow as shown in fig 3 The following steps 5 6 describe the dismantling of clutch 5 Stretch out the springs with circlip pliers and press them out from the clutch hub 6 A complete clutch or springs ar...

Page 28: ...brake must be in the off position 1 Fit the clutch shoes on the hub and fit the springs with circlip pliers See fig 4 Fig 5 Fig 6 NOTE The clutch springs must not opened more than is necessary Risk of deformation min 3 5 mm 2 Fit the clutch hub on the crankshaft and tighten with the clutch tool Note left hand thread See fig 6 3 Remove the piston stop and fit the spark plug and put on the ignition ...

Page 29: ...ual Bar guide plate clutch drum and the centrifugal clutch See page 26 fig 1 and 2 3 Dismantle the oil pump gear A See fig 1 4 Remove the two bolts B and lift up the oil pump from the crankcase See fig 2 5 Use a screwdriver to push up the oil hose at C Lift up the hose and pull it out of the oil pump See fig 2 6 Use pointed pliers and pull up the suction pipe D with filter See fig 2 7 Removethecli...

Page 30: ...e See fig 2 2 Put the spring K 2 washers J on pump piston I and fit in the pump housing Oil in all parts with chain oil See fig 3 3 Use a screwdriver to press in the pump piston and screw home the adjuster screw F See fig 3 4 Fit the cover plug H See fig 3 5 Fit the clip E See fig 3 6 Fit the oil pump in the crankcase Fit the oil hose with seals See fig 2 7 Tighten the bolts to 5 Nm See fig 6 8 Fi...

Page 31: ...The mixing venturi B in fig 2 The pump unit C in fig 3 The jets and the fuel s control functions are located in the metering unit A Here the correct quantity of fuel is adjusted for the actual speed and power output The mixing venturi B houses the choke throttle valve and diffuser jets Here air is mixed with the fuel to give a fuel air mixture that can be ignited by the ignition spark In the pump ...

Page 32: ...I is partly open Extra air inlet J is closed In the idling mode fig 5 the throttle valve I and J is closed Air is sucked in through an aperture in the throttle valve and a small amount of fuel is supplied through the diffuser jet D In the part throttle mode fig 6 the throttle valve I is partially open Fuel is supplied through the diffuser jets D and E In full throttle mode fig 7 all valves are ope...

Page 33: ...r cover and air filter 2 Remove the carburettor control D by pulling Disconnect switch wires E and F See fig 8 3 Unhook the throttle cable A See fig 8 4 Remove the fuel pipe B 5 Remove 4 bolts G which secure the filter holder carburettor and choke system 6 Loosen the filter holder and disconnect the rear rubber mounts H See fig 9 7 Removethefilterholderwithcarburettorandchoke system See fig 9 Fig ...

Page 34: ...r the pump unit and carefully remove the gasket I and pump diaphragm H and G NOTE The carburettor has two diaphragms One pump diaphragm G and one backup diaphragm H See fig 11 11 Use a needle or the like to carefully remove the fuel filter F See fig 11 12 Remove caps with the high and low speed screws NOTE Both needles are fitted with O rings See fig 13 13 If necessary remove the throttle and chok...

Page 35: ...ig 10 11 and 12 and check the following 1 That gaskets pump and control diaphragms are undamaged 2 That there is no play on the throttle and choke valve shafts 3 The needle valves and lever are not worn at C and D in fig 10 4 The fuel filter is undamaged See L in fig 11 5 The tips of the high and low speed screws are not damaged 6 The intake manifold is undamaged See page 44 7 The carburettor has ...

Page 36: ...il 2 Fit the high and low speed screws and springs Note Do not fully tighten the screws This will damage the seats and needle tips 3 Fit the fuel filter F by using the handle of a small screwdriver See fig 14 4 Fit the pump diaphragmas G and H gasket I and cover J on the pump unit See fig 14 5 Fit the needle valve D with lever C spindle and spring and tighten the screw E Fit welch plug K See fig 1...

Page 37: ...Pump up the pressure to 50 kPa 0 5 bar 5 No leakage is permitted If a leakage occurs refer to the table below Fig 17 Fig 18 Leakage at Fault with Diffuser jets Needle valve Leakage in impulse tube Pump diaphragm Ventilation hole Control diaphragm on metering unit Fig 19 7 Fit the control diaphragm B with gasket and cover A on the metering unit See fig 17 8 Fit the axle L on the air shutter and con...

Page 38: ...e choke is fitted in the right position in the partition See page 47 fig 15 2 Mount 4 bolts G which secure the filter holder carburettor and choke system 3 Mount the fuel pipe B 4 Connect the throttle cable A 5 Connect the switch wires E and F 6 Mount the carburettor control D 7 Fit the cylinder cover and air filter See the Operator s Manual Fig 20 Fig 21 G H H B A D F E ...

Page 39: ...e fixed on the needles The adjustment sleeve then can be removed Over the caps on complete sparepart carburettor there is a plastic sleeve which is intended to lock the caps at the richest position anticlockwise towards stop during the time that the needles are adjusted When the adjustment is complete and the caps have been fixed on the needles the sleeve is no longer of any function and can be re...

Page 40: ...570 D 1 5 576XP G D 1 5 3 Press a new L cap on the L needle to the first stop which means that the cap is not fixed to the needle it should rotate independently 4 Adjust the L cap to the richest position turned counterclockwise to stop without turning the needle 5 Let the engine run at E app 1 minute until warm and then let it run on idle Model 570 E 13 000 576XP G E 13 000 6 Adjust the idle speed...

Page 41: ... Turn off the motor and remove the cylinder cover 3 Screw the air screw turn clockwise with screwdri ver 530 03 55 60 Fig 1 Make sure the rotation angle of the throttle axle changes by looking at the movement of the lever arm Fig 2 Then replace the cylinder cover warm up the motor and test the product again 4 Repeat steps 2 and 3 a maximum of 4 times 1 turn until the motor accelerates well 5 Check...

Page 42: ...Fig 3 NOTE Take care not to damage the fuel pipe and throttle cable E 2 x G H D F A C D B E 7 If necessary lift out the fuel pipe and pull off the fuel filter D Fig 1 Tank valve Thetankvalve C isatwo wayvalveandhasthefollowing features Controlled opening pressure in both directions which prevents excess of pressure or vacuum developing in the fuel tank and impairing engine operation Resistant to c...

Page 43: ...the engine unit over the tank unit and push the fuel tankvent pipe and throttle cable into their holes in the bottom of the carburettor space 4 Fit the bolts E and H See fig 2 Tighten the bolts to the torque in the service data page 10 and 11 5 Fit front handle with the bolts D F and G See fig 2 Tighten the bolts to the torque in the service data page 10 and 11 6 Fit the fuel pipe B on the carbure...

Page 44: ...nd front handle 2 Removethespringonthecylinderwitha4mmAllen key See fig 1 3 Remove the springs on the tank unit with a 4 mm Allen key See fig 2 Cleaning and inspection Clean and inspect all parts Assembly 1 Fit the springs on the cylinder and tank with a 4 mm Allen key See fig 1 and fig 2 Note Harder springs are available Should only be used together with longer guide bars See IPL for part number ...

Page 45: ...e off carbon deposits from the following surfaces 1 The piston crown 2 Top of the cylinder bore inside 3 The cylinder exhaust port 4 The decompression valve NOTE Exercise care so that dirt and foreign partic les do not get into the crankcase A C A B Bx3 Fig 4 5 Cover the crankcase opening immediately with a sheet of paper or a cloth See fig 2 6 Remove one of the piston s circlips press out the gud...

Page 46: ...That the piston is free of score marks Minor scratches can be polished off with fine emery paper 4 That the piston ring is not burnt into its groove 5 Measure the wear on the piston ring by placing it at the bottom of the cylinder and measuring the gap See fig 6 The clearance must not exceed 1 mm 6 That the needle bearing is undamaged 7 That the intake manifold and it s rubber seals are undamaged ...

Page 47: ...ct impuls hose and fit into possition See fig 10 4 Fit the decompression valve B See fig 12 Tighten it to 15 Nm 5 Fit the gasket on the cylinder base Press it up so that it fastens on the sleeve of the cylinder 6 Oil in the piston ring and sides of the piston with two stroke oil 7 Compressthepistonring eitherbyhandorwithtool 502 50 70 01 See fig 11 Carefully fit on the cylinder A B Faults and caus...

Page 48: ...linder See fig 12 Tighten the bolt to 10 Nm 10 Pressure test as shown in page 36 Fig 13 D E A G H I K J F Manifold The intake system has two inlets 1 The upper intake I and E lets fuel and air mixture from carburettor into the cylinder D 2 The lower intake K and F lets air into the cylinder 3 The impuls hose J is separately connected to the cylinder 4 Note The insert ring should have the notch poi...

Page 49: ...e shaft P in notch Slide choke rod N in guide O Push in the choke rod Q The impuls nipple should meet the impuls hose R Tighten the screws 2 Nm Connect the rear rubber mount S See fig 15 13 Assemble the following parts Muffler See page 15 Cylinder cover See the Operator s Manual Chain and bar See the Operator s Manual 14 If a new piston and or cylinder is fitted the chainsaw should be run in for 3...

Page 50: ...stead of spark plug See fig 18 The decompression valve should be closed 3 Pump up the pressure to 80 kPa 0 8 bar 4 Wait 30 seconds 5 The pressure must not fall below 60 kPa 0 6 bar 6 Leakage can occur in the decompression valve and crankshaft seals 7 Pressure test the decompression valve as follows Se also fig 19 A Connect preasure test tool 531 03 06 23 to the decompression valve B Pump up the pr...

Page 51: ...and foreign partic les do not get into the bearing 2 Remove the carburettor space bottom by unscrewing the four bolts See fig 1 3 If necessary remove the seal on the flywheel side Use tool 504 91 40 01 See page 53 fig 14 4 Remove the six bolts on the flywheel side See fig 2 5 Fit tool 502 52 49 01 as shown in fig 3 and remove the crankcase half on the flywheel side 6 Remove the crankcase half on t...

Page 52: ...asketmaterial from the mating surfaces of the crankcase halves Check the following 1 That the big end bearing does not have any radial play Axial play is acceptable 2 That the big end bearing does not have any score marks or is discoloured on the sides See fig 7 3 That the bearing surfaces for the little end do not have any score marks or are discoloured See fig 8 4 That the crankshaft main bearin...

Page 53: ...foreign partic les do not get into the bearing D Fit the rubber stop A See fig 5 E Fit the oil filler cap 2 When fitting new seals the sealing surfaces should begreasedin Whenfittingthesealontheflywheels side use tool 502 50 30 20 The seal on the clutch side is fitted in the ball bearing The seals can also be fitted when the crankshaft is in place NOTE Make sure that the connecting rod does not ja...

Page 54: ...gasket material does not fall into the crankcase 7 Cut off the gasket at the level of the cylinder base 8 Fit the carburettor space bottom with the four bolts Tighten the bolts to 5 Nm 9 Assemble the following parts A Tank unit B Piston and cylinder C Muffler D Carburettor E Lubrication system F Centrifugal clutch G Electrical system H Starter I Chain and bar See the Operator s Manual 10 If a new ...

Page 55: ...0 See fig 15 4 Fit the parts in accordance with pos 1 above Bar bolts 1 Drain off the chain oil 2 Tapintheoldbarboltfromoutsidesothatitdropsin the oil tank 3 Remove the bolt from the oil tank 4 Fix a piece of steel wire on the end of the new bolt and pull it through the oil tank and out through the bolt hole in the crankcase See fig 16 5 Pull the steel wire so that the bolt comes into its hole 6 P...

Page 56: ...e listed to the right The most likely fault is listed first etc Starting difficulties The carburettor leaks fuel Floods when the engine is not running Clogged air filter Choke does not work Worn choke shaft Worn choke valve The fuel filter is clogged The fuel line is clogged Piston ring is stuck Blocked impulse channel Loose or defective fuel hose Hole in the membrane Control system is jamming Con...

Page 57: ...run at full throttle Low on power Too lean Blocked air filter Tank venting clogged The fuel filter is clogged The fuel line is clogged Loose or defective fuel hose Impulse channel leaking Blocked impulse channel The cover on the carburettor pump side is loose Faulty pump diaphragm Leaking inlet hose rubber Loose clamping screws carburettor Control system set too low Control system damaged Control ...

Page 58: ...2015 08 31 115 59 20 26 ...

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