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STIH)

STIHL MS 460

2004-11

Summary of Contents for MS 460

Page 1: ...STIH STIHL MS 460 2004 11 ...

Page 2: ... Removing 31 6 5 2 Installing 32 6 6 Piston Rings 36 6 7 Crankcase 36 6 7 1 Removing the Crankshaft 36 6 7 2 Installing the Crankshaft 39 6 8 Decompression Valve 44 7 Ignition System 44 7 1 Ignition Module 45 7 1 1 Ignition Timing 45 7 1 2 Removing and Installing 45 7 1 3 Testing the Ignition Module 47 7 2 Spark Plug Boot Ignition Lead 48 7 3 Flywheel 49 7 3 1 Removing 49 7 3 2 Installing 50 7 4 S...

Page 3: ... Cap 72 12 4 2 Basic Setting Carburetor with Limiter Caps 72 12 5 Tank Vent 73 12 6 Pickup Body 74 12 7 Fuel Hose 75 12 8 Tank Housing 75 13 Carburetor Heating System 78 13 1 Testing 79 13 2 Troubleshooting Chart 80 13 3 Heating Element with Thermostatic Switch 81 14 Handle Heating System 81 14 1 Troubleshooting 81 14 1 1 Troubleshooting Chart 83 14 1 2 Test Connections and Test Values 85 14 2 Hea...

Page 4: ... in the text and pictures for greater clarity The meanings are as follows In the descriptions Action to be taken as shown in the illustration above the text Action to be taken that is not shown in the illustration above the text Situation applies from serial No Situation applies up to serial No In the illustrations A Pointer short arrow aDirection of movement long arrow b 4 2 Reference to another ...

Page 5: ...s and warnings in the instruction manual Gasoline is an extremely flammable fuel and can be explosive in certain conditions Improper handling may result in burns or other serious injuries Warning Do not bring any fire flame spark or other source of heat near the fuel All work with fuel must be performed outdoors only Spilled fuel must be wiped away immediately 2 Safety Precautions ...

Page 6: ... 500 rpm Crankcase leakage test at gauge pressure 0 5 bar under vacuum 0 5 bar 3 2 Fuel System Carburetor leakage test at gauge pressure 0 8 bar Operation of tank vent at gauge pressure 0 3 bar Fuel as specified in instruction manual 3 3 Ignition System Air gap between ignition module and fanwheel 0 15 0 3 mm Spark plug suppressed Bosch WSR 6F NGK BPMR 7 A Electrode gap 0 5 mm 3 4 Chain Lubricatio...

Page 7: ...x1 Decompression valve 14 0 Nut M5 Filter cover 1 0 Collar nut M5 SK6 Flange air filter 6 0 Screw B 4 2x9 5 Spark arresting screen Z version only 6 Screw IS M4x12 Generator W version only 3 5 1 7 Screw IS P6x21 5 Handlebar top 8 0 1 Screw IS P6x19 Handlebar bottom 8 0 1 Screw IS P4x19 Handle molding 1 6 Screw IS M5x35 Hand guard left 7 0 Screw IS M5x16 Shroud crankcase 7 0 Locknut M5 Chain catcher...

Page 8: ...eel 33 0 Screw IS M4x12 Segment fan housing 2 5 Screw IS M4x8 Inner side plate 3 0 Nut M5 Carburetor 3 5 Screw IS M6x30 Cylinder Crankcase 15 0 Spark plug M14x1 25 Spark plug 25 0 Screw IS M5x20 Ignition module 7 0 Remarks 2 Secure with Loctite 243 4 Secure with high strength Loctite 272 5 Only version with catalytic converter Screws secured with adhesive are easier to loosen if the adhesive is he...

Page 9: ...the clutch springs Clutch spring hooks broken Replace the clutch springs Loud noises Clutch springs stretched or fatigued Replace all clutch springs Needle cage damaged Fit new needle cage Clutch shoe retainer broken Fit new retainer Clutch shoes and carrier worn Install new clutch Chain sprocket wears rapidly Chain not properly tensioned Tension chain as specified Wrong chain pitch Fit chain of c...

Page 10: ...be pulled out almost without resistance crankshaft does not turn Guide peg on pawls or pawls themselves are worn Fit new pawls Spring clip fatigued Fit new spring clip Starter rope is difficult to pull and rewinds very slowly Starter mechanism is very dirty very dusty work area Clean complete starter mechanism Lubricating oil on rewind spring becomes viscous at very low outside temperatures spring...

Page 11: ...ed or intake hose ruptured Clean suction hose and pickup body strainer with a little standard solvent based degreasant containing no chlorinated or halogenated hydrocarbons or replace if necessary Valve in oil tank blocked Clean replace valve Teeth on pump piston and or worm worn Install new oil pump and or new worm Machine losing chain oil O ring on oil line in crankcase seat faulty or oil line d...

Page 12: ...k ignition lead for break If break is detected or high resistance measured fit a new ignition lead Incorrect air gap between ignition coil and flywheel Set air gap correctly Flywheel cracked or has other damage or pole shoes have turned blue Install new flywheel Crankcase damaged cracks Replace crankcase Check operation of spark plug Inspect Master Control lever ignition coil lead for damage insul...

Page 13: ...constantly against the inlet control lever Fit a new metering diaphragm Inlet control lever too high relative to correct installed position Set inlet control lever flush with top edge of housing Poor acceleration Idle jet too lean Rotate low speed screw L counterclockwise richer no further than stop Main jet too lean Rotate high speed screw H counterclockwise richer no further than stop Inlet cont...

Page 14: ...rectly Small plastic plate in valve jet does not close Clean or renew valve jet Engine speed drops quickly under load low power Air filter dirty Clean the air filter Tank vent faulty Clean tank vent or replace if necessary Fuel pickup body dirty Clean the pickup body fit a new filter Fuel strainers dirty Replace the fuel strainers Leak in fuel line between tank and fuel pump Seal connections or in...

Page 15: ...l or replace the muffler Engine does not deliver full power or runs erratically Piston rings worn or broken Fit new piston rings Muffler spark arresting screen carbonized Clean the muffler inlet and exhaust replace spark arresting screen Air filter element dirty Replace air filter element Fuel impulse line severely kinked or damaged Replace lines or position them free from kinks Decompression valv...

Page 16: ...et 3 VA 148RA061 3 2 1 Pull off the clutch drum 1 with needle cage 2 Inspect the needle cage for damage VA 148RA062 1 2 Inspect the clutch drum 1 for signs of wear If there are signs of serious wear on the inside diameter of the clutch drum 1 check the remaining wall thickness If it is less than about 80 of the original thickness fit a VA 148RA101 80 100 1 new clutch drum If the clutch drum has to...

Page 17: ...drum chain sprocket and apply slight pressure at the same time until the oil pump drive spring engages the notch see arrow t Remove the chain sprocket cover b 5 1 Remove screw 1 from chain catcher 2 and lift away the chain catcher Install in the reverse sequence VA 176RA000 2 1 Troubleshooting b 4 1 Remove the clutch drum or chain sprocket b 5 1 Loosen the twist lock 1 and lift off the carburetor ...

Page 18: ...68 Disassembling Use hook 2 5910 890 2800 to remove the clutch springs 1 Pull the clutch shoes off the carrier VA 208RA028 2 1 Pull the retainers off the clutch shoes VA 208RA031 Clean all parts b 16 Replace any damaged parts VA 208RA026 Installing Push the retainers onto the clutch shoes VA 208RA029 Fit the clutch shoes over the arms 1 of the clutch carrier so that the series number 2 is on the s...

Page 19: ...ctivating the brake and the saw chain coming to a complete standstill The shorter the braking time the better the efficiency and protection offered against being injured by the rotating chain Contamination with chain oil chips fine particles of abrasion etc and smoothing of the friction surfaces of the brake band and clutch drum impair the coefficient of friction This in turn reduces the frictiona...

Page 20: ...e spring by pushing hand guard forward VA 176RA026 Carefully ease the brake spring 1 off the anchor pin and take it off the bell crank 2 VA 176RA027 1 2 Take out the screw arrow VA 176RA028 Pry the brake band out of the crankcase VA 176RA029 Remove the brake band 1 from the lugs on the crankcase Disconnect the brake band from the bell crank 2 VA 176RA030 1 2 Install a new brake band if there are n...

Page 21: ...Pull off the cam lever 3 Inspect parts and replace if VA 176RA034 3 1 4 2 damaged Clean the entire housing recess for the chain brake If the groove in the anchor pin for the brake spring is worn install a new pin Remove the cylinder b 6 5 1 Use a suitable punch to drive the anchor pin 1 out of the crankcase in the direction of the arrow Do not drive out the pin in the other direction as this would...

Page 22: ...pin Fit the E clip 2 1 1 2 1 1 2 VA 176RA037 Attach the spring 1 to the pivot pin 2 and cam lever 3 Inspect the heat reflecting foil on the hand guard and replace if necessary VA 176RA038 2 1 3 Push bell crank into the side of the hand guard The short arm arrow of the bell crank must point to the top of the hand guard VA 176RA040 Position the hand guard 1 against the pivot pin and fit the other si...

Page 23: ...tite and fit b 16 Tighten down the screw firmly b 3 5 VA 176RA045 The turns of brake spring must be tightly against one another in the relaxed condition If this is not the case replace the brake spring Check correct position of protective tube a a b VA 176RA046 a 20 mm b 32 mm Attach brake spring to bell crank arrow VA 176RA047 Use assembly tool 2 1117 890 0900 to attach the brake spring 1 to the ...

Page 24: ...e plate b 5 4 2 Rotate the spur gear clockwise until tensioner slide 1 butts against the thrust pad 2 VA 176RA052 2 1 Pull out the retainer 1 Take out the screw 2 VA 176RA053 1 2 Remove the cover plate VA 176RA054 Pull out the spur gear VA 176RA055 Take out the tensioner slide with adjusting screw and thrust pad VA 176RA056 Inspect the teeth on the spur gear and adjusting screw 1 replace both part...

Page 25: ... puller 1 5910 893 0501 over the collar stud as far as it will go Use a 15 mm wrench to unscrew the collar stud counterclockwise VA 176RA117 1 Before installing coat thread of collar stud with Loctite b 16 Install and tighten down the collar stud b 3 5 Always check and if necessary repair the fuel system carburetor air filter and ignition system before looking for faults on the engine Troubleshoot...

Page 26: ...ing screen or fit a new one if necessary VA 176RA060 Catalytic converter machines only If there are signs of cracks in the honeycomb core 1 or if the steel jacket is damaged the catalytic converter must be replaced to avoid the risk of VA 176RA324 1 engine damage Inspect the heat reflecting foil and replace if necessary b 6 7 2 VA 176RA061 Place heat shield 1 in position Install a new gasket 2 so ...

Page 27: ...akes adjustment of the prescribed idle speed difficult if not impossible Moreover the transition from idle speed to part or full throttle is not smooth The crankcase can be checked thoroughly for leaks with the carburetor and crankcase tester and the vacuum pump Remove the decompression valve b 6 8 Install plug 1 1122 025 2200 and tighten down to 25 Nm Fit spark plug 2 and tighten it down b 3 5 VA...

Page 28: ...200 is in hole No 1 arrow fit if necessary VA 176RA017 1 Push the test flange 1 into position When fitting the test flange make sure the pin locates properly in the impulse hose 2 Fit the sleeves 3 VA 176RA013 3 4 1 2 0000 963 1008 Fit the nuts 4 and tighten them down firmly Preparations b 6 2 1 Connect pressure hose 1 of tester 1106 850 2905 to nipple arrow on test flange VA 176RA014 Close vent s...

Page 29: ... Connect suction hose arrow of vacuum pump 0000 850 3501 to nipple arrow of the test flange VA 176RA014 Close the vent screw 1 on the pump Operate lever 2 until pressure gauge 3 indicates a vacuum of 0 5 bar VA 176RA018 3 1 2 If the vacuum reading remains constant or rises to no more than 0 3 bar within 20 seconds it can be assumed that the oil seals are in good condition However if the pressure c...

Page 30: ...dard solvent based degreasant containing no chlorinated or halogenated hydrocarbons b 16 Lubricate sealing lips of oil seal with grease b 16 Thinly coat the outside diameter of the oil seal with sealant b 16 Slip the oil seal open side facing the crankcase over the crankshaft stub Use press sleeve 1 1115 893 4600 to install the oil seal The seating face must be flat and free from burrs Wait about ...

Page 31: ...93 4602 onto the crankshaft stub VA 176RA024 1 Slip the oil seal open side facing the crankcase over the crankshaft stub Use press sleeve 1 1118 893 2401 to install the oil seal VA 176RA025 1 Remove the installing sleeve Wait about one minute then rotate the crankshaft several times Install retaining ring in crankshaft groove If the retaining ring is fatigued fit a new one Install the oil pump b 1...

Page 32: ...spark plug b 5 3 Remove the shroud b 6 4 Remove the carburetor b 12 2 1 If a decompression valve is fitted remove the cover 1 and unscrew the valve 2 VA 176RA072 2 1 Take the sleeve 1 out of the manifold Remove the washer 2 from the studs VA 176RA261 1 2 Take out the cylinder base screws through the holes arrows in the cylinder VA 176RA069 Carefully lift the cylinder and at the same time push the ...

Page 33: ...r eyes when working with spring washers and snap rings VA 176RA074 Use the assembly drift 2 0000 893 4700 to push the piston pin 1 out of the piston If the piston pin is stuck tap the end of the drift lightly with a hammer if necessary Hold the piston steady during this VA 176RA075 2 1 process to ensure that no jolts are transmitted to the connecting rod Remove the piston from the connecting rod a...

Page 34: ...he large slotted diameter of the sleeve over the magnet and snap ring Position the sleeve so that the inner pin 1 points toward the flat face 2 of tool s shank VA 249RA146 2 1 Stand the installing tool sleeve downward on a flat surface wooden board and press vertically downwards until the sleeve butts against the tool s shoulder VA 249RA147 Remove the sleeve and slip it onto the other end of the s...

Page 35: ...ttention to the correct installed position arrow VA 176RA083 Push the hose clamp 1 over the manifold The screw head must point to the right Tighten down the clamp so that it closes against the spacer sleeve VA 176RA084 1 On hose clamps without spacer sleeve tighten the screw until the gap between the two ends of the clamp is 5 6 mm Use the clamping strap 1 0000 893 2600 to compress the rings aroun...

Page 36: ... manifold down Pull the ends of the string outward The manifold flange is pulled through the tank housing intake opening without damaging the manifold VA 176RA089 Check that flange is properly seated in the tank housing Fit sleeve 1 in manifold Fit the washer 2 on the studs Install all other parts in the reverse sequence VA 176RA066 1 2 Line up the cylinder and gasket Tighten down the cylinder bas...

Page 37: ... 5 1 Drain the oil tank Drain the fuel tank Dispose of fuels and lubricants properly in accordance with local environmental requirements Pull the worm with drive spring arrow out of the oil pump and off the crankshaft VA 176RA093 Take out the screws arrows Remove the oil pump VA 176RA094 Take the sealing ring arrow out of the housing bore Remove the piston b 6 5 1 Remove the ignition module b 7 1 ...

Page 38: ...he two halves of the crankcase Pull the heat reflecting foil off the crankcase VA 176RA104 At the chain tensioner side of the crankcase use a 5 mm drift 2 to drive the dowel pin out of the two halves of the crankcase VA 176RA106 1 2 Back off the spindle 1 of service tool AS 5910 007 2205 all the way Slip service tool AS 2 over the two collar studs Fit the hex nuts 3 for sprocket VA 176RA107 2 3 1 ...

Page 39: ...s and oil seals Use press arbor 1 1120 893 7200 to press the ball bearing out of the crankcase from the outside inwards VA 176RA112 1 Use press arbor 1 1118 893 7200 to press the ball bearing out of the crankcase from the inside outwards Inspect both halves of the crankcase for cracks and replace if necessary VA 176RA113 1 The crankcase must be replaced as a complete unit even if only one half is ...

Page 40: ...ers the suction hose and oil tank cap are removed before the crankcase is heated If the original crankcase is used again remove all gasket residue and clean the mating surfaces thoroughly to guarantee a perfect seal If a new crankcase is installed the following additional operations are necessary Install the chain brake b 5 4 3 Fit the bar mounting studs b 5 6 Install the chain tensioner b 5 5 The...

Page 41: ... cord 1 in the groove 2 and pull it forward VA 176RA122 2 1 Place the oil pump in position Insert screws and tighten them down firmly b 3 5 Heat the area of the ball bearing on the clutch side of the crankcase to about 150 C VA 176RA123 302 F Place the ball bearing with shoulder 1 on the inside of the crankcase and push it home by hand against the oil pump This operation must be carried out very q...

Page 42: ...d sleeve 1 5910 893 2420 onto the spindle VA 176RA128 1 2 Lubricate tapered stub of crankshaft with oil Place tapered stub of crankshaft in ball bearing at the flywheel side of the crankcase VA 176RA129 Screw threaded sleeve 1 to thread 2 of crankshaft stub VA 176RA130 2 1 Hold the spindle steady and rotate the service tool counter clockwise until the drilled plate butts against the crankcase VA 1...

Page 43: ... 176RA136 AS 5910 890 2205 Screw threaded sleeve 1 5910 893 2409 of service tool AS 5910 890 2205 onto the spindle as far as stop left hand thread VA 176RA137 1 Push the threaded sleeve over the crankshaft stub Hold the crankshaft steady and rotate the spindle counter clockwise to screw the threaded sleeve onto the crankshaft VA 176RA138 Release the crankshaft Hold the service tool steady and cont...

Page 44: ...ide the oil seal open side facing the crankcase over the ignition end of the crankshaft Use press sleeve 1 1115 893 4600 to press home the oil seal The press surface must be flat and free from burrs VA 176RA142 1 Fit the assembly sleeve 1 1118 893 2401 over the clutch end of the crankshaft VA 176RA143 1 Slide the oil seal open side facing the crankcase over the assembly sleeve Use press sleeve 1 1...

Page 45: ... the cover 1 Unscrew the decompression valve 2 Install in the reverse sequence VA 176RA147 2 1 Fit the decompression valve and tighten it down firmly b 3 5 Fit the cover 1 Fit the shroud b 6 4 Exercise extreme caution when troubleshooting or carrying out maintenance and repair work on the ignition system The high voltages that occur can cause serious or even fatal accidents Troubleshooting on the ...

Page 46: ...checking that wiring and stop switch are in good condition Ignition timing is fixed and cannot be adjusted during repair or servicing work Since there is no mechanical wear in these systems ignition timing cannot get out of adjustment as a result of wear Remove the shroud b 6 4 Remove the fan housing with rewind starter b 8 2 Pull the short circuit wire 1 off the connector tag on the ignition modu...

Page 47: ...ed handles position the wire with connector under the ignition module and in the retainers arrows VA 176RA150 Rotate the flywheel until the two raised portions arrow are in line with the ignition module VA 176RA155 Slide the setting gauge 1 1111 890 6400 between the arms of the ignition module and the raised edge of the flywheel Press the ignition module against the setting gauge VA 176RA156 1 Tig...

Page 48: ...3 ignition tester 5910 850 4520 It is necessary to use the ZAT 3 ignition tester 5910 850 4520 to test the booster gap Before starting the test install a VA 208RA054 ZAT 3 5910 850 4520 3 2 1 new spark plug in the cylinder and tighten it down firmly b 3 5 Remove spark plug boot and connect it to terminal 2 Attach ground terminal 1 to the spark plug Use adjusting knob 3 to set spark gap to about 2 ...

Page 49: ... the boot off the ignition lead VA 176RA159 Cut new ignition lead to a length of 150 mm Coat end of ignition lead about 20 mm with oil Fit the spark plug boot over the ignition lead Use suitable pliers to grip the end of the ignition lead inside the spark plug boot and pull it out Use a pointed tool to pierce the center of the ignition lead s insulation about 15 mm from the end of the lead Pinch t...

Page 50: ...e ignition module Push the grommet over the high voltage output Install the ignition module b 7 1 2 Remove the fan housing with rewind starter b 8 2 Use locking strip to block the piston b 5 3 Unscrew the flywheel nut arrow VA 176RA163 Screw puller 1 1110 890 4500 into the flywheel Screw home the thrust bolt until the flywheel is released VA 176RA164 1 Pull off the flywheel Remove the puller from ...

Page 51: ...ch housing until the switch actuator is exposed Pull out the switch actuator 1 and spring 2 VA 176RA166 2 1 Carefully push the switch housing sideways and lift it away When installing push home the switch actuator until it snaps into position VA 176RA167 Remove the ignition module b 7 1 On machines with heated handles pull pin connector 1 out of the socket 2 VA 176RA168 1 2 Pull the grommet arrow ...

Page 52: ...s the wires into their retainers Fit the grommets properly in the openings in the tank housing If the spark plug and ignition lead with spark plug boot are in order check the resistance of the short circuit wire ground wire and contact spring VA 135RA111 Pull the short circuit wire arrow off the tag on the ignition module Connect the ohmmeter to ground and the short circuit wire Set Master Control...

Page 53: ...Smeared with oil black Sooted Electrode gap correct Contacts shorted Clean the plug reset or replace Check spark plug boot Firmly seated on plug leg spring Leg spring hook in center of ignition lead Boot damaged If necessary install new spark plug boot and or leg spring Test ignition system with ZAT 3 or ZAT 4 use ZAT 3 as main spark gap see TI 32 94 1 ...

Page 54: ...if necessary Check ignition lead Severe chafing Spark plug boot Holes cracks Resistance spark plug boot to ground spec 1 5 12k Check resistance of ignition lead spec 10 If necessary install new spark plug boot and or ignition lead Disconnect short circuit wire from ignition module 1 3 yes no Powerful spark 2 ...

Page 55: ...in fuel system or carburetor check engine for leaks check position of flywheel on crankshaft yes Check operation of Master Control lever or separate stop switch Short circuit wire chafed Contact gap contact springs If necessary install new ignition lead and or contact springs Re connect short circuit wire 2 3 Powerful spark Engine runs ...

Page 56: ...action is restored If clogged with dirt or pitch the entire starter mechanism including the rewind spring must be removed and disassembled Take particular care when removing the spring Clean all components b 16 Before installing lubricate the rewind spring and starter post with STIHL special lubricant b 16 Remove the screws arrows from the fan housing Remove the fan housing with rewind starter Ins...

Page 57: ...r or pliers to carefully remove the spring 1 from the starter post VA 176RA176 1 Remove the washer 1 from the starter post Remove the pawls Carefully pull the rope rotor off the starter post VA 176RA177 1 Remove the starter rope from the rotor b 8 4 Install a new starter rope b 8 5 Tension the rewind spring b 8 5 1 Install in the reverse sequence Remove the fan housing with rewind starter b 8 2 Pr...

Page 58: ...he rewind spring b 8 5 1 VA 176RA179 Remove the fan housing with rewind starter b 8 2 Relieve tension of rewind spring b 8 4 Make a loop in the starter rope VA 176RA191 Grip the rope next to the rotor and use it to turn the rope rotor six times clockwise VA 176RA192 Hold the rope rotor steady Pull out the rope with the starter grip and straighten it out Hold the starter grip firmly to keep the rop...

Page 59: ...l of the bushing eventually wears through and the bushing becomes loose Remove the fan housing with rewind starter b 8 2 Remove the rope rotor b 8 4 Pull knot 1 out of recess 2 in rope rotor Undo the knot Pull the starter rope out of the rotor and guide bushing VA 176RA187 2 1 Use a suitable tool to pry the damaged bushing out of the fan housing Installing the rope guide bushing Place the new bush...

Page 60: ... fan housing VA 146RA196 The anchor loop must be above the lug in the fan housing Position suitable tools on the recesses arrows and push the spring into its seat in the fan housing If the rewind spring pops out during installation fit it in the installing tool 1116 893 4800 as follows Position the anchor loop about 25 mm from the edge of the spring housing VA 138RA109 Fit the rewind spring in the...

Page 61: ...ther rubber buffers b 12 8 Pry the annular buffers arrows out of the crankcase VA 176RA196 Push the stop buffer out of its seat and take it away VA 176RA197 Push the stop buffer into the guide so that the groove 1 engages the housing rib 2 VA 176RA198 1 2 At the clutch side push the annular buffer home from the outside so that its groove 1 engages the housing rib 2 VA 176RA199 2 1 At the starter s...

Page 62: ...rom carburetor b 12 2 1 Disconnect short circuit wire 1 and ground wire 2 from the contact springs VA 176RA202 2 1 Take out the switch shaft mounting screw arrow VA 176RA203 Carefully ease the switch shaft out of its left hand mount 1 and then pull the switch housing 2 out of the right hand mount VA 176RA204 2 1 Machines with heated handles Remove the switch shaft from under the wire to the rear h...

Page 63: ... spring 3 VA 176RA215 1 2 3 Remove the torsion spring from the throttle trigger VA 176RA216 The torsion spring must be fitted under the interlock lever and locate in the notch arrow VA 138RA128 Machines with heated handles The wires from the heating element must be under the interlock lever arrow and locate in the channel VA 176RA217 Press the interlock lever 1 down Pull the throttle trigger 2 up ...

Page 64: ...ssary Troubleshooting b 4 3 Pickup body Drain the oil tank Collect chain oil in a clean container or dispose of it properly at an approved disposal site Use hook 1 5910 893 8800 to pull the pickup body out of the oil tank Do not stretch the oil hose during this operation VA 176RA232 1 Pull the pickup body out of the suction hose Fit a new pickup body Flush out the oil tank Install in the reverse s...

Page 65: ... oil in a clean container or dispose of it properly at an approved disposal site Remove the inner side plate b 5 4 2 Blow the valve 1 clear with compressed air from outside to inside of tank Flush out the oil tank Fit the inner side plate b 5 4 2 VA 175RA021 1 Fit the oil tank cap Unscrew the oil tank cap Remove the inner side plate b 5 4 2 Use a 5 mm drift to carefully drive the valve out of the ...

Page 66: ... grease before installing b 16 176RA247 VA Check the suction hose and pickup body before disassembling the oil pump Remove the oil pump b 11 3 1 Use a 2 mm drift to drive out the spring pin 1 VA 176RA248 5 6 7 7 3 2 4 1 Pull out the control bolt 2 Remove the O rings 3 Pry out the plug 4 Remove the pump piston 5 with spring 6 and washers 7 Clean all parts and examine for serviceability b 16 Install...

Page 67: ... Wash the air filter thoroughly in a fresh non flammable cleaning solution and blow out with compressed air Replace if damaged VA 176RA251 Pull off the baffle in the direction of the arrow VA 176RA252 Unscrew the collar nuts 1 Pull off the flange 2 VA 176RA253 2 1 Remove the filter base arrow Wash the filter mesh in the filter base thoroughly in a fresh non flammable cleaning solution and blow out...

Page 68: ...ting VA 176RA258 Pull the heating element off the studs Separate pin and socket connection for thermostatic switch b 13 3 VA 176RA259 Pull off the carburetor Reassemble in the reverse sequence VA 176RA260 Before fitting the carburetor check that the sleeve 1 and washer 2 are in place VA 176RA261 1 2 When pushing the carburetor into position check that the impulse hose 1 and fuel hose 2 are correct...

Page 69: ...e carburetor is airtight However if it drops there are two possible causes 1 The inlet needle is not sealing foreign matter in valve seat or sealing cone of inlet needle is damaged or inlet control lever sticking Remove to clean b 12 3 2 2 Metering diaphragm damaged replace if necessary b 12 3 1 After completing the test open the vent screw 1 and pull the fuel line off the carburetor Push the fuel...

Page 70: ...the screw arrow Remove the inlet control lever with spindle VA 176RA278 There is a small spring under the inlet control lever which may pop out during disassembly Take out the inlet needle If there is an annular indentation on the sealing cone of the inlet needle fit a new inlet needle VA 176RA279 Fit the inlet needle 1 Fit spring 2 in bore Insert spindle 3 in the inlet control lever 4 Engage clev...

Page 71: ...aphragm and gasket Inspect diaphragm for damage and wear fit a new gasket VA 176RA268 The diaphragm material as well as the inlet and outlet valves are subjected to continuous alternating stresses and eventually show signs of fatigue i e the diaphragm distorts and swells and has to be replaced Check fuel strainer 1 for contamination and damage If necessary use a needle to take it out of the carbur...

Page 72: ...ce as necessary Check and clean or replace spark arresting screen if fitted Check chain tension Warm up the engine Adjust idle speed Adjusting idle speed Adjust idle speed with a tachometer Adjust specified engine speeds within tolerance of 200 rpm 1 Adjust engine speed with idle VA 176RA295 speed screw LA to 3 300 rpm 2 Turn low speed screw L clockwise or counterclockwise to obtain maximum engine...

Page 73: ...meter Adjust specified engine speeds within tolerance of 200 rpm 1 Adjust engine speed with idle speed screw LA to 3 300 rpm 2 Turn low speed screw L clockwise or counterclockwise to obtain maximum engine speed If this speed is higher than 3 700 rpm abort the procedure and start again with step 1 3 Use the idle speed screw LA to set engine speed again to 3 300 rpm 4 Set the engine speed to 2 500 r...

Page 74: ...ise or counterclockwise to obtain maximum engine speed If this speed is higher than 3 700 rpm abort the procedure and start again with step 1 3 Use the idle speed screw LA to set engine speed again to 3 300 rpm 4 Set the engine speed to 2 500 rpm with the low speed screw L 5 Set engine s maximum speed to 13 500 rpm with the high speed screw H 6 Install new limiter caps noting that the stop lugs on...

Page 75: ... passage of fuel and results in fuel starvation In the event of trouble with the fuel supply system always check the fuel tank and the pickup body first Clean the fuel tank if necessary Cleaning the fuel tank VA 176RA296 1 Remove the fuel tank cap 1 and drain the tank Pour a small amount of clean gasoline into the tank Close the tank and shake the machine vigorously Open the tank again and drain i...

Page 76: ... little oil Straight side 1 of flange must VA 176RA301 1 locate against the tank housing Drain the fuel tank Drain the oil tank Collect fuel in a clean container or dispose of it properly at an approved disposal site Remove the carburetor b 12 2 1 Take the sleeve 1 out of the manifold and pull the washer 2 off the studs VA 176RA302 1 2 Remove the mounting screws from the side of the front handle H...

Page 77: ...ch b 14 2 Disconnect short circuit wire 1 and ground wire 2 from the contact springs VA 176RA304 1 2 Ease the plug arrow out of the annular buffer at the starter side VA 176RA305 Take the screw arrow out of the buffer Remove the inner side plate b 5 4 2 VA 176RA306 Remove the chain catcher b 5 2 Take the plugs arrows out of the annular buffers at the clutch side VA 176RA307 Take out the annular bu...

Page 78: ...a thread insert Drill out stripped thread to a diameter of a Ø 8 5 mm and a a b VA 176RA334 depth of b 15 mm Caution Do not exceed the specified hole depth of 15 mm Fit an M6x10 screw with washer in the thread insert Screw the thread insert into the tank housing VA 176RA312 An M6x18 screw must then be used in place of the original self threading screw Install in the reverse sequence To pull the ma...

Page 79: ...screws with Loctite b 16 Tighten down the screws firmly VA 176RA313 b 3 5 Install all other parts in the reverse sequence Current is supplied via wires to the heating element installed between the baffle plate and carburetor Carburetor heating is controlled by a thermostatic switch on the heating element The carburetor heating system should be checked if running problems occur when the cold engine...

Page 80: ... socket connector to heating element Clip one test lead to the metal of the heating element and the other test lead to the wire that 100 50 30 20 10 5 0 20 10 5 3 1 VA 176RA315 goes to the heating element If the heating element is in good condition the ohmmeter will show a reading of about 8 in measuring range If the reading obtained is outside this tolerance install a new heating element Thermost...

Page 81: ... Check thermostatic switchn no Replace heating element Does thermostatic switch open between 6 C 43 F and 13 C 55 F Does thermostatic switch close between 13 C 55 F and 6 C 43 F Carburetor heating system in order Resistance approx 8 Ohm no no yes yes yes Replace thermostatic switch Replace thermostatic switch ...

Page 82: ...e are two reasons for failures in the heating system 1 A break in the circuit due to a faulty wire or component 2 A short circuit resulting from damage to the insulation The heating element in the rear handle may overheat and fail if it is not bonded firmly in position i e completely flat no creases Tracing the cause of a fault VA 176RA338 Remove the interlock lever b 10 2 Push back the insulating...

Page 83: ...ing of about 8 in measuring range If no reading is obtained there is a break in the circuit If the ohmmeter shows a very low value there is a short circuit in one of the components In either case it is necessary to check each component separately b 14 1 The generator wire remains disconnected from the heating element during this check After completing the test reconnect the wires and push the insu...

Page 84: ...e of individual heating elements with ohmmeter On machines with carburetor heating pull connector pins of wires from heating element on carburetor out of round plug no yes Turn on switch yes Resistance of rear handle heating element about 1 Check rear handle heating element In good condition Bonding ok Heater switch on no no no Install new rear handle heating element Install new generator yes yes ...

Page 85: ... about 0 Open Circuit interrupted On machines with carburetor heating refit connector pin of wire from heating element in the round plug no no Install new front handle Install new heater switch yes yes Test ground wire between tank housing and crankcase Resistance between switch housing and crankcase about 0 no Install new wiring harness yes 1 2 3 ...

Page 86: ...ing element in rear handle Terminal socket on wire from rear handle heating element Terminal pin on wire from rear handle heating element 1 0 0 8 1 2 Heating element OK Break in wire heating element damaged Install new heating element or repair insulation 0 Short circuit damaged insulation Heating element in front handle Connector on wire from front handle heating element Ground 7 0 6 0 8 0 Heatin...

Page 87: ... lead Resistance If faulty Lead 1 Lead 2 Spec Actual Cause Remedy Generator WVH Connector on gen s red wire Ground 0 8 0 6 1 0 Generator OK Generator WVH and W Break in wire generator damaged Install new generator 0 Short circuit damaged insulation Repair insulation ...

Page 88: ...e into the switch Push the rubber grommet over the switch Push the wire into the retainer Install the carburetor b 12 2 1 Remove the interlock lever b 10 2 Slide the two insulating tubes 1 off the pin and socket connectors and separate the connectors 1 VA 176RA225 Take pressure pad and heating element out of the handle recess Before fitting the new heating element clean the surface inside the hand...

Page 89: ... heating switched on The heating element in the front handle handlebar is not replaceable A new handle must be fitted if the heating element is faulty Remove the carburetor b 12 2 1 Remove the interlock lever b 10 2 Slide the insulating tube off the pin and socket connector of the wire between the front handle heating element and the rear handle heating element Separate the pin and socket connecto...

Page 90: ...es for cracks or other damage If damage is found replace the generator VA 176RA239 Inspect the magnet ring arrow in the flywheel for cracks or other damage If damage is found replace the flywheel Reassemble in the reverse sequence VA 176RA240 Place the generator in position with the connecting wire 1 facing the crankcase Connecting wire must locate in the crankcase recess 2 Coat screw threads with...

Page 91: ...15 893 4600 Installing oil seal starter side 16 Assembly sleeve 1118 893 4602 Protecting oil seal at clutch side 17 Press sleeve 1118 893 2401 Installing oil seal clutch side 18 Assembly drift 1111 893 4700 Removing and installing piston pin 19 Installing tool 12 5910 890 2212 Fitting hookless snap rings in piston 20 Stud puller M8 5910 893 0501 Removing bar mounting studs 21 Assembly tool 1116 89...

Page 92: ...124 5910 893 5608 Flywheel nut 37 Socket 19 mm DIN 3124 5910 893 5613 Clutch 38 Screwdriver bit T 27 x 125 0812 542 2104 Removing and installing spline socket head screws with electric or pneumatic screwdrivers tighten down screws with torque wrench 39 T handle screwdriver T 27 x 150 5910 890 2400 IS P screws 4 mm 1 40 Press arbor 1118 893 7200 Removing and installing ball bearing clutch side 41 P...

Page 93: ...in rope rotor rewind spring in fan housing 4 Dirko sealant grey 100 g tube 0783 830 2120 Oil seals outside 5 Standard commercial solvent based degreasant containing no chlorinated or halogenated hydrocarbons Cleaning sealing faces 6 STIHL multipurpose grease 0781 120 1109 High voltage output on ignition module 7 Medium strength threadlocking adhesive Loctite 242 0786 111 1101 8 High strength threa...

Page 94: ...englisch english 0455 176 0123 M7 L4 Fi Printed in Germany ...

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