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Wacker Neuson WM 90 Repair Manual

Summary of WM 90

  • Page 1

    Www.Wackergroup.Com engine wm 90 repair manual 0160157en 002 0207 0 1 6 0 1 5 7 e n.

  • Page 3: Wm 90 Repair

    Wm 90 repair foreword wc_tx000387gb.Fm 3 operating / parts information you must be familiar with the operation of this machine before you attempt to troubleshoot or repair it. Basic operating and maintenance procedures are described in the operator’s manual supplied with the machine. Keep a copy of ...

  • Page 4: Foreword

    Foreword wm 90 repair wc_tx000387gb.Fm 4 california proposition 65 warning: engine exhaust, some of its constituents, and certain vehicle components, contain or emit chemicals known to the state of california to cause cancer and birth defects or other reproductive harm. Laws pertaining to spark arre...

  • Page 5: Wm 90 Repair

    Wm 90 repair table of contents wc_br0160157en_002toc.Fm 5 1. Emission control system information 8 2. Safety information 13 2.1 operating safety ................................................................................ 14 2.2 operator safety while using internal combustion engines ..............

  • Page 6: Table of Contents

    Table of contents wm 90 repair wc_br0160157en_002toc.Fm 6 6. Dissassembly/reassembly general information 40 6.1 tools ....................................................................................................40 6.2 ordering parts ...............................................................

  • Page 7: Wm 90 Repair

    Wm 90 repair table of contents wc_br0160157en_002toc.Fm 7 8.16 adjusting governor system ................................................................ 67 8.17 installing muffler ................................................................................. 67 8.18 installing blower housing and...

  • Page 8

    Emission control system information 8 1. Emission control system information source of emissions the combustion process produces carbon monoxide, oxides of nitrogen, and hydrocarbons. Control of hydrocarbons and oxides of nitrogen is very important because, under certain conditions, they react to fo...

  • Page 9

    Emission control system information 9 replacement parts the emission control systems on your wacker engine were designed, built, and certified to conform with epa and california emissions regulations. We recommend the use of genuine wacker parts whenever you have maintenance done. These original-des...

  • Page 10

    Emission control system information 10 methanol - (methyl or wood alcohol) 5% by volume. You may use gasoline containing up to 5% methanol by volume, as long as it contains cosolvents and corrosion inhibitors to protect the fuel system. Gasoline containing more than 5% methanol by volume may cause s...

  • Page 11

    Emission control system information 11 (i) intake manifold, if applicable. (ii) air filter. (3) ignition system (i) spark plugs. (ii) magneto or electronic ignition system. (iii) spark advance/retard system, if applicable. (4) exhaust manifold, if applicable (5) miscellaneous items used in above sys...

  • Page 12

    Emission control system information 12 you are responsible for presenting your engine to the nearest service dealer authorized by wacker when a problem exists. If you have any questions regarding your warranty rights and responsibilities, you should contact the wacker corporation product support dep...

  • Page 13: Wm 90 Repair

    Wm 90 repair safety information wc_si000143gb.Fm 13 2. Safety information this manual contains danger, warning, caution, notice and note callouts which must be followed to reduce the possibility of personal injury, damage to the equipment, or improper service. This is the safety alert symbol. It is ...

  • Page 14: Safety Information

    Safety information wm 90 repair wc_si000143gb.Fm 14 2.1 operating safety familiarity and proper training are required for the safe operation of machine. Machines operated improperly or by untrained personnel can be dangerous. Read the operating instructions contained in both this manual and the engi...

  • Page 15: Wm 90 Repair

    Wm 90 repair safety information wc_si000143gb.Fm 15 2.1.18 always guide the rammer in such a way that the operator is not squeezed between the rammer and solid objects. Special care is required when working on uneven ground or when compacting coarse material. Make sure to stand firmly when operating...

  • Page 16: Safety Information

    Safety information wm 90 repair wc_si000143gb.Fm 16 2.3 service safety poorly maintained machines can become a safety hazard! In order for the machine to operate safely and properly over a long period of time, periodic maintenance and occasional repairs are necessary. 2.3.1 do not attempt to clean o...

  • Page 17: Wm 90 Repair

    Wm 90 repair safety information wc_si000143gb.Fm 17 2.4 label locations.

  • Page 18: Safety Information

    Safety information wm 90 repair wc_si000143gb.Fm 18 2.5 safety labels wacker machines use international pictorial labels where needed. These labels are described below: label meaning this molded-in label contains important safety and operating information. If it becomes illegi- ble, the cover must b...

  • Page 19: Wm 90 Repair

    Wm 90 repair safety information wc_si000143gb.Fm 19 caution! Use only clean, filtered gasoline fuel. Warning! Hot surface! Warning! Serious injury if struck by compressed spring or cover. If the spring system cover is removed improperly, the springs can eject. Guaranteed sound power level in db(a). ...

  • Page 20: Safety Information

    Safety information wm 90 repair wc_si000143gb.Fm 20 a nameplate listing the model number, item number, revision number, and serial number is attached to each unit. Please record the infor- mation found on this plate so it will be available should the nameplate become lost or dam- aged. When ordering...

  • Page 21: Wm 90 Repair

    Wm 90 repair safety information wc_si000143gb.Fm 21 2.6 operating labels wacker machines use international pictorial labels where needed. These labels are described below: label meaning turn the engine switch to the on position. Close the choke. Pull the rewind starter. Open the choke. Turn the engi...

  • Page 22: Safety Information

    Safety information wm 90 repair wc_si000143gb.Fm 22 throttle control lever: turtle = idle or slow rabbit = full or fast fuel valve: closed open engine stop button: press to stop engine. Choke: 0 = open l = closed label meaning.

  • Page 23: Wm 90

    Wm 90 technical data wc_td000143gb.Fm 23 3. Technical data 3.1 specifications engine model wm 90 engine engine speed - full rpm 4200 ± 100 engine speed - idle rpm 2000 ± 100 clutch engagement rpm 2500 ± 100 spark plug type ngk bm4a or bmr4a electrode gap mm (in) 0.6–0.7 (0.023–0.028) cylinder head c...

  • Page 24: Technical Data

    Technical data wm 90 wc_td000143gb.Fm 24 3.2 performance ref description ref description a maximum torque d recommended horsepower range b continuous rated horsepower e output c maximum horsepower f torque.

  • Page 25: Wm 90

    Wm 90 theory of operation wc_tx000388gb.Fm 25 4. Theory of operation 4.1 application rammers are designed to compact loose soils and gravel to prevent settling and to provide a firm, solid base for the placement of footings, concrete slabs, foundations, and other structures. 4.2 recommended fuel thi...

  • Page 26: Theory of Operation

    Theory of operation wm 90 wc_tx000388gb.Fm 26 4.4 to start see graphic: wc_gr001454 note: after transporting the rammer horizontally, upright the rammer and allow the oil to drain back through the engine. It may take up to 2 minutes for the oil level to recover. 4.4.1 open fuel valve (e). 4.4.2 turn...

  • Page 27: Wm 90

    Wm 90 theory of operation wc_tx000388gb.Fm 27 4.5 to stop see graphic: wc_gr001454 4.5.1 place throttle in the idle position (c2). 4.5.2 turn engine switch to "off" (d). 4.5.3 close fuel valve (e). 4.6 component descriptions component illustration component description the cylinder/crankcase is a si...

  • Page 28: Theory of Operation

    Theory of operation wm 90 wc_tx000388gb.Fm 28 the crankshaft is forged carbon steel, and the crank pin is induction-hardened. The output end of the shaft has a crankshaft gear that is pressed into position. The connecting rod is an aluminum alloy die- casting and its large and small ends function as...

  • Page 29: Wm 90

    Wm 90 theory of operation wc_tx000388gb.Fm 29 the intake valve is located on the flywheel side of the cylinder head. Hard alloy valve seats are molded in the cylinder head and satellite is fused to the exhaust valve face. The cylinder baffle leads cooling air to the exhaust valve area for optimum co...

  • Page 30: Theory of Operation

    Theory of operation wm 90 wc_tx000388gb.Fm 30 the large fins (a) on the flywheel provide suffi- cient cooling air capacity for the inlet and exhaust area and cylinder. The cylinder baffle directs the cooling air flow efficiently. All the rotating and sliding parts are splash- lubricated by the oil s...

  • Page 31: Wm 90

    Wm 90 theory of operation wc_tx000388gb.Fm 31 wm 90 engines use a diaphragm-type carbu- retor. The air cleaner is a heavy-duty three-stage type with cyclonic precleaner. An automatic decompression mechanism (a), that opens the exhaust valve before the piston reaches maximum compression, is assembled...

  • Page 32: Theory of Operation

    Theory of operation wm 90 wc_tx000388gb.Fm 32 4.7 cross section across shaft wc_gr001884 2 3 7 8 8 9 9 10 11 12 13 1 1.

  • Page 33: Wm 90

    Wm 90 theory of operation wc_tx000388gb.Fm 33 4.8 cross section across shaft components see graphic: wc_gr001884 . Ref description ref description 1 cylinder head 9 main bearing cover 2 piston pin 10 pto shaft 3 ignition coil 11 piston ring 4 blower housing 12 piston 5 recoil starter 13 muffler 6 fl...

  • Page 34: Theory of Operation

    Theory of operation wm 90 wc_tx000388gb.Fm 34 4.9 cross section along shaft 1 4 10 14 g.

  • Page 35: Wm 90

    Wm 90 theory of operation wc_tx000388gb.Fm 35 4.10 cross section along shaft components see graphic: wc_gr001885 . Ref description ref description 1 push rod 9 stiffener 2 carburetor 10 plug 3 air cleaner 11 oil gauge 4 tappet 12 connecting rod 5 camshaft 13 spark plug 6 governor lever 14 rocker arm...

  • Page 36: Maintenance

    Maintenance wm 90 repair wc_tx000392gb.Fm 36 5. Maintenance 5.1 periodic maintenance schedule before each use every 50 hours every 100 hours every 300 hours every 500 hours or yearly check for fluid leaks. Check engine oil. Check fuel level. Check for loose hardware. Clean debris from engine. Change...

  • Page 37: Wm 90 Repair

    Wm 90 repair maintenance wc_tx000392gb.Fm 37 5.2 servicing air cleaner see graphic: wc_gr001306 never use gasoline or other types of low flash point solvents for cleaning the air filter. A fire or explosion could result. Notice: never run the engine without the main paper air filter (b). Severe engi...

  • Page 38: Maintenance

    Maintenance wm 90 repair wc_tx000392gb.Fm 38 5.3 servicing fuel filter and fuel tank see graphic: wc_gr002017 5.3.1 drain fuel tank completely. 5.3.2 remove fuel line from fuel flow valve (a). 5.3.3 unscrew fuel filter assembly (b) from tank. 5.3.4 clean filter with parts cleaning solvent. 5.3.5 ins...

  • Page 39: Wm 90 Repair

    Wm 90 repair maintenance wc_tx000392gb.Fm 39 5.4 long-term storage 5.4.1 drain the fuel from the tank. 5.4.2 start the engine and run it until remaining fuel is used. 5.4.3 remove the spark plug. Pour approximately 30 ml (1 oz.) of clean sae 10w30 engine oil into the cylinder through the spark plug ...

  • Page 40: Wm 90 Repair

    Dissassembly/reassembly general information wm 90 repair wc_tx000389gb.Fm 40 6. Dissassembly/reassembly general information 6.1 tools because all possible problems encountered while repairing the machine cannot be anticipated, it is up to the mechanic to use common sense and good judgement in tool s...

  • Page 41: Wm 90 Repair

    Wm 90 repair disassembly procedures wc_tx000389gb.Fm 41 7. Disassembly procedures 7.1 removing engine from rammer see graphic: wc_gr001954, wc_gr003661, wc_gr001956, and wc_gr001957 7.1.1 disconnect the spark plug cap (a) from the spark plug. 7.1.2 disconnect the fuel line (b) from the carburetor an...

  • Page 42: Disassembly Procedures

    Disassembly procedures wm 90 repair wc_tx000389gb.Fm 42 d e j f wc_gr001954 b l a c k wc_gr003661.

  • Page 43: Wm 90 Repair

    Wm 90 repair disassembly procedures wc_tx000389gb.Fm 43 7.2 draining oil see graphic: wc_gr001886 note: in the interests of environmental protection, place plastic sheeting and a container under the machine to collect the liquid which drains off. Dispose of this liquid properly. 7.2.1 remove the dra...

  • Page 44: Disassembly Procedures

    Disassembly procedures wm 90 repair wc_tx000389gb.Fm 44 7.3 removing recoil starter and blower housing see graphic: wc_gr003650 7.3.1 remove the bolts (a) and remove the recoil starter (b) from the housing. 7.3.2 remove the flange bolts (f), cap screw (g), and remove the blower housing (h). Wc_gr003...

  • Page 45: Wm 90 Repair

    Wm 90 repair disassembly procedures wc_tx000389gb.Fm 45 7.4 removing muffler see graphic: wc_gr001888 7.4.1 remove the flange nuts (a). 7.4.2 remove the flange bolts (b). 7.4.3 remove the bolts and washers (c) and remove the muffler (d) and the gasket (e)..

  • Page 46: Disassembly Procedures

    Disassembly procedures wm 90 repair wc_tx000389gb.Fm 46 7.5 removing governor lever, carburetor, speed control lever see graphic: wc_gr001890 7.5.1 mark the hole in which the governor spring (a) is attached and remove the spring. 7.5.2 loosen the m6 bolt (b) and remove the governor lever (c). 7.5.3 ...

  • Page 47: Wm 90 Repair

    Wm 90 repair disassembly procedures wc_tx000389gb.Fm 47 7.6 removing ignition coil, flywheel, and spark plug see graphic: wc_gr001891 7.6.1 remove the spark plug (a). 7.6.2 remove the two m6 x 25 bolts (b) and remove the ignition coil (c). 7.6.3 remove the m12 nut and washer (d), four m6 bolts (e), ...

  • Page 48: Disassembly Procedures

    Disassembly procedures wm 90 repair wc_tx000389gb.Fm 48 7.7 removing rocker cover and cylinder head see graphic: wc_gr001892 7.7.1 remove the four m6 x 60 bolts (a) and remove the rocker cover (b) and gasket (c). 7.7.2 remove the breather (d), gaskets (e), and spacer (f). 7.7.3 remove the two m8 x 5...

  • Page 49: Wm 90 Repair

    Wm 90 repair disassembly procedures wc_tx000389gb.Fm 49 7.8 removing bearing cover see graphic: wc_gr001893 7.8.1 remove the nine m6 x 30 bolts and washers (a) and remove the main bearing cover (b). Note: if necessary, use a rubber mallet (c) and tap the cover to loosen it from the crankcase. Wc_gr0...

  • Page 50: Disassembly Procedures

    Disassembly procedures wm 90 repair wc_tx000389gb.Fm 50 7.9 removing camshaft and tappets see graphic: wc_gr001894 7.9.1 lay crankcase on the flywheel side and push the tappets (a) into the crankcase and remove the camshaft (b). A b b wc_gr001894.

  • Page 51: Wm 90 Repair

    Wm 90 repair disassembly procedures wc_tx000389gb.Fm 51 7.10 removing connecting rod and piston see graphic: wc_gr001895 7.10.1 remove connecting rod bolts (a) and connecting rod cap (b). 7.10.2 turn crankshaft until piston (c) comes to top dead center, push out connecting rod (d) and piston assembl...

  • Page 52: Disassembly Procedures

    Disassembly procedures wm 90 repair wc_tx000389gb.Fm 52 7.11 removing crankshaft see graphic: wc_gr001896 7.11.1 to remove the crankshaft (a), tap lightly on flywheel end of the crankshaft with a rubber mallet (b). A b wc_gr001896.

  • Page 53: Wm 90 Repair

    Wm 90 repair disassembly procedures wc_tx000389gb.Fm 53 7.12 removing intake and exhaust valves see graphic: wc_gr001897 note: the procedure is the same for removing each valve. 7.12.1 remove pivot bolt (a), rocker arm (b), and nut (c). 7.12.1 press down the spring retainer (d), take out the collet ...

  • Page 54: Reassembly Procedures

    Reassembly procedures wm 90 repair wc_tx000389gb.Fm 54 8. Reassembly procedures 8.1 notes on reassembly observe the following prior to/during reassembly of the engine: • clean each part carefully, taking special care with the piston, cylinder, crankshaft, connecting rod, and bearings. • scrape off a...

  • Page 55: Wm 90 Repair

    Wm 90 repair reassembly procedures wc_tx000389gb.Fm 55 8.3 reassembling piston see graphic: wc_gr001874, wc_gr001899 and wc_gr001900 install each piston ring in the correct groove of the piston by widening it enough to slide it over the piston. Note: when installing the piston rings, make sure not t...

  • Page 56: Reassembly Procedures

    Reassembly procedures wm 90 repair wc_tx000389gb.Fm 56 8.4 reassembling piston and connecting rod see graphic: wc_gr001901 8.4.1 install the piston (a) onto the connecting rod (b) using the piston pin (c) and two clips (d). D d a c b wc_gr001901.

  • Page 57: Wm 90 Repair

    Wm 90 repair reassembly procedures wc_tx000389gb.Fm 57 8.5 installing piston see graphic: wc_001902, wc_gr001903, and wc_gr001904 8.5.1 position the piston rings so that the gaps in the rings are at 90° intervals from each other (a = top ring, b = second ring, c = oil ring). 8.5.2 apply oil to the p...

  • Page 58: Reassembly Procedures

    Reassembly procedures wm 90 repair wc_tx000389gb.Fm 58 8.6 installing tappets and camshaft see graphic: wc_gr001905 8.6.1 oil the tappets (a) and install them. Push them in fully to avoid damage during camshaft (b) installation. 8.6.2 remove spacer (c) to allow viewing of timing mark. 8.6.3 lubricat...

  • Page 59: Wm 90 Repair

    Wm 90 repair reassembly procedures wc_tx000389gb.Fm 59 8.7 adjusting crankshaft end play see graphic: wc_gr001906 adjust the end play to 0.2 mm (0.008 in.) using the proper spacer. Determine the proper spacer in the following manner: 8.7.1 measure the height “a”. Distance from main bearing cover mat...

  • Page 60: Reassembly Procedures

    Reassembly procedures wm 90 repair wc_tx000389gb.Fm 60 8.8 installing main bearing cover see graphic: wc_gr001907 8.8.1 lubricate the oil seal and bearing surfaces with engine oil. 8.8.2 coat the mating surfaces of the main bearing cover (a) and crankcase (b) with loctite ® 515 gasket eliminator or ...

  • Page 61: Wm 90 Repair

    Wm 90 repair reassembly procedures wc_tx000389gb.Fm 61 8.9 cylinder head 8.9.1 clean carbon and gum deposits from the valves, seats, ports, and guides. Inspect them once clean. Replace valves that are badly burned, pitted, or warped. 8.9.2 when installing valves in cylinder head, oil the valve stems...

  • Page 62: Reassembly Procedures

    Reassembly procedures wm 90 repair wc_tx000389gb.Fm 62 8.10 reassembling rocker arms and push rods see graphic: wc_gr001908 8.10.1 insert push rods (a) into crankcase. Place push rod tip into the hollow of the tappet top. Notice: an oil return slot is located next to the tappet boss. If you do not p...

  • Page 63: Wm 90 Repair

    Wm 90 repair reassembly procedures wc_tx000389gb.Fm 63 8.11 adjusting valve clearances see graphic: wc_gr001909 and wc_gr001910 note: check and adjust valve clearances when engine is cold. 8.11.1 temporarily fit the flywheel in position. 8.11.2 position the piston at the top dead center of the compr...

  • Page 64: Reassembly Procedures

    Reassembly procedures wm 90 repair wc_tx000389gb.Fm 64 8.12 installing rocker cover and spark plug see graphic: wc_gr001911 note: replace the gasket with a new one each time the rocker cover is removed. 8.12.1 using four m6 bolts (a), secure the rocker cover (b) and gasket (c) to the cylinder head. ...

  • Page 65: Wm 90 Repair

    Wm 90 repair reassembly procedures wc_tx000389gb.Fm 65 8.13 installing flywheel magneto 8.13.1 place the woodruff key in the keyway of the crankshaft. Thoroughly wipe off oil and grease from the tapered portion of the crankshaft and also from the flywheel center hole. 8.13.2 install the flywheel, m1...

  • Page 66: Reassembly Procedures

    Reassembly procedures wm 90 repair wc_tx000389gb.Fm 66 8.15 installing governor, speed control system, and carburetor see graphic: wc_gr001890 8.15.1 install governor lever (a) to governor shaft, then tighten the locking bolt (b) temporarily. 8.15.2 install baseplate (t) to crankcase using two m6 x ...

  • Page 67: Wm 90 Repair

    Wm 90 repair reassembly procedures wc_tx000389gb.Fm 67 8.16 adjusting governor system see graphic: wc_gr001914 8.16.1 turn the speed control lever (a) all the way toward the high speed position and secure it by tightening the self-locking screw. 8.16.2 check that the governor lever (b) is pulled by ...

  • Page 68: Reassembly Procedures

    Reassembly procedures wm 90 repair wc_tx000389gb.Fm 68 8.18 installing blower housing and recoil starter see graphic: wc_gr003650 8.18.1 install the blower housing (h) using the flange bolts (f) and cap screw (g). 8.18.2 install the recoil starter (b) to the housing using the bolts (a). Wc_gr003650 ...

  • Page 69: Wm 90 Repair

    Wm 90 repair reassembly procedures wc_tx000389gb.Fm 69 8.19 re-installing engine see graphic: wc_gr001954, wc_gr003661, wc_gr001956, and wc_gr001957 8.19.1 position the engine so that mounting studs protrude from the adapter plate mounted to the rammer crankcase. Position heatshield and secure engin...

  • Page 70: Reassembly Procedures

    Reassembly procedures wm 90 repair wc_tx000389gb.Fm 70 d e j f wc_gr001954 b l a c k wc_gr003661.

  • Page 71: Wm 90 Repair

    Wm 90 repair reassembly procedures wc_tx000389gb.Fm 71 8.20 break-in operation a new engine or one that has been completely overhauled by being fitted with a new piston, rings, valves, and connecting rod should be thoroughly run-in before being put into service. Good bearing surfaces and running cle...

  • Page 72: Sub Systems

    Sub systems wm 90 repair wc_tx000390gb.Fm 72 9. Sub systems 9.1 magneto the ignition system of the wm 90 is a breakerless flywheel magneto with an automatic advancing system. This system has no breaker points and thus is free from the starting and running problems associated with dirty, burnt, or co...

  • Page 73: Wm 90 Repair

    Wm 90 repair sub systems wc_tx000390gb.Fm 73 9.3 electrical components see graphic: wc_gr001916 ref description ref description 1 low-speed ignition timing circuit 9 spark plug 2 signal transistor a 10 ignition timing (btdc) 3 automatic advancing control circuit 11 engine revolution (rpm) 4 signal t...

  • Page 74: Sub Systems

    Sub systems wm 90 repair wc_tx000390gb.Fm 74 9.4 automatic decompression system see graphic: wc_gr001917 wm 90 engines employ an automatic decompression system as a standard feature. This system enables easy starting of the engine, with lighter recoil pull. The automatic decompression system release...

  • Page 75: Wm 90 Repair

    Wm 90 repair sub systems wc_tx000390gb.Fm 75 9.5 diaphragm-type carburetor see graphic: wc_gr001919 ref description comment 1 engine impulse the alternating action of the positive pressure and neg- ative pressure inside the engine crankcase operates the fuel pump diaphragm. 2 fuel pump diaphragm the...

  • Page 76: Sub Systems

    Sub systems wm 90 repair wc_tx000390gb.Fm 76 13 metering chamber the metering chamber is the fuel storage compartment that has the function of supplying fuel to the nozzle holes and other parts. 14 first idle hole the first idle hole is the only fuel supply hole that is available when the engine is ...

  • Page 77: Wm 90 Repair

    Wm 90 repair sub systems wc_tx000390gb.Fm 77 9 12 11 7 17 20 6 4 5 2 19 18 3 1 8 15 14 16 13 10 wc_gr001919.

  • Page 78: Sub Systems

    Sub systems wm 90 repair wc_tx000390gb.Fm 78 9.6 carburetor disassembly procedure see graphic: wc_gr001920 prior to disassembling the carburetor, wash it with an appropriate cleaning solvent. 9.6.1 loosen the pump cover screw (14) and remove the screw and the pump cover (13). 9.6.2 remove the pump g...

  • Page 79: Wm 90 Repair

    Wm 90 repair sub systems wc_tx000390gb.Fm 79 9.7 carburetor inspection see graphic: wc_gr001920 9.7.1 clean the carburetor and components with an appropriate solvent. 9.7.2 check the gaskets for any deformation and/or damage. Replace any deformed or damaged gaskets. 9.7.3 make sure that the pump dia...

  • Page 80: Sub Systems

    Sub systems wm 90 repair wc_tx000390gb.Fm 80 9.9 carburetor adjustments see graphic: wc_gr001920 idling adjustment: 9.9.1 start the engine and adjust the idle adjust screw (15) so that the engine is running at a speed slightly lower than the speed at which the clutch engages. High-speed adjustment: ...

  • Page 81: Wm 90 Repair

    Wm 90 repair recoil starter wc_tx000627gb.Fm 81 10. Recoil starter 10.1 recoil starter disassembly see graphic: wc_gr001830 wear eye protection when working on the recoil starter. To release the reel spring power: 10.1.1 hold the starter knob and pull out the starter rope. 10.1.2 pull out the rope f...

  • Page 82: Recoil Starter

    Recoil starter wm 90 repair wc_tx000627gb.Fm 82 see graphic: wc_gr001831 to remove the components: 10.1.6 grip the case (a) and loosen the set screw (b). 10.1.7 remove, in this order: the set screw, the ratchet guide (c), the friction spring (d), and the ratchet (e). See graphic: wc_gr001831 remove ...

  • Page 83: Wm 90 Repair

    Wm 90 repair recoil starter wc_tx000627gb.Fm 83 reassembly see graphic: wc_gr001832 re-installing the reel: 10.1.11 apply grease (exxon unirex or equivalent) (a) to the surface of the case. 10.1.12 adjust the position of the inner end of the spring reel. Reference (b): position where the inner end o...

  • Page 84: Recoil Starter

    Recoil starter wm 90 repair wc_tx000627gb.Fm 84 see graphic: wc_gr001835 tensioning the reel spring: 10.1.17 grip the case and turn the reel 6 times counterclockwise. 10.1.18 rotate the reel so that the rope hole (a) is aligned with the rope guide (b). See graphic: wc_gr001836 and wc_gr001837 instal...

  • Page 85: Wm 90 Repair

    Wm 90 repair recoil starter wc_tx000627gb.Fm 85 10.2 checking the recoil starter after reassembly note: carry out the following procedures to ensure proper operation of the starter assembly. 10.2.1 pull the starter rope 2–3 times. • if the starter knob is too heavy to pull, check that each part has ...

  • Page 86: Recoil Starter

    Recoil starter wm 90 repair wc_tx000627gb.Fm 86 10.3 starter assembly exploded view see graphic: wc_gr002880 for machines with item numbers 0009386 rev. 112 and higher; 0009340 rev. 112 and higher; 0620051 rev. 108 and higher ref description ref description 1 starter assembly 8 spring 2 rope 9 ratch...

  • Page 87: Wm 90 Repair

    Wm 90 repair recoil starter wc_tx000627gb.Fm 87 10.4 disassembling the starter see graphic: wc_gr002880 10.4.1 remove the starter assembly from the fan cover and release the spring tension as described in section replacing the starter rope. 10.4.2 untie the rope (2) and remove the handle (3). 10.4.3...

  • Page 88: Recoil Starter

    Recoil starter wm 90 repair wc_tx000627gb.Fm 88 rope check the rope length. It is 150 cm (60 in.) when new. If the rope is too short, it may bottom out when pulled and damage the starter. 10.6 assembling the starter see graphic: wc_gr002880 and wc_gr002881 10.6.1 clean all the components of the star...

  • Page 89: Wm 90 Repair

    Wm 90 repair recoil starter wc_tx000627gb.Fm 89 10.6.4 lightly grease the center post of the housing and install the wear plate (4) and the rope reel pulley. Rotate the rope reel pulley until the spring seats in the slot at the center of the housing (13). Install the washer (7) over the center post ...

  • Page 90: Recoil Starter

    Recoil starter wm 90 repair wc_tx000627gb.Fm 90 wc_gr002882 a d e b c.

  • Page 91: Wm 90 Repair

    Wm 90 repair clearance data and limits table wc_tx000391gb.Fm 91 11. Clearance data and limits table 11.1 term descriptions the following table lists critical dimensions of specific parts. The “standard” column lists the dimension of the part as new from the factory. The “limit” column lists the max...

  • Page 92: Wm 90 Repair

    Clearance data and limits table wm 90 repair wc_tx000391gb.Fm 92 piston outer diameter at skirt in thrust direction std 50.97–50.99 (2.0067–2.0075) 50.88 (2.0031) oversize (+0.25) 51.22–51.24 (2.0165–2.0173) 51.13 (2.0123) oversize (+0.50) 51.47–51.49 (2.0264–2.0272) 51.38 (2.0228 ring groove-side c...

  • Page 93: Wm 90 Repair

    Wm 90 repair clearance data and limits table wc_tx000391gb.Fm 93 clearance between piston and cylinder at skirt 0.010–0.049 (0.0004–0.0019) 0.25 (0.010) piston ring end gap top ring 0.15–0.35 (0.006–0.014 1.5 (0.0591) 2nd ring 0.35–0.55 (0.014–0.022 1.5 (0.0591) oil ring 0.05–0.25 (0.002–0.010 1.5 (...

  • Page 94: Wm 90 Repair

    Clearance data and limits table wm 90 repair wc_tx000391gb.Fm 94 connectng rod large-end inner diameter 20.000–20.013 (0.7874–0.7879) 20.1 (0.7913) clearance between large end and crank pin 0.037–0.063 (0.0015–0.0025) 0.2 (0.008) small end inner diameter 11.010–11.021 (0.4335–0.4339) 11.08 (0.4362) ...

  • Page 95: Wm 90 Repair

    Wm 90 repair clearance data and limits table wc_tx000391gb.Fm 95 large end side clearance 0.1–0.7 (0.004–0.028) 1.0 (0.04) crankshaft crank pin outer diameter 19.950–19.963 (0.7854–0.7859) 19.85 (0.7815) journal outer diamete r d 1 and d 2 19.988–19.997 (0.7869–0.7873) --- camshaft cam peak height (...

  • Page 96: Wm 90 Repair

    Clearance data and limits table wm 90 repair wc_tx000391gb.Fm 96 journal outside diameter d 1 9.972–9.987 (0.3926–0.3932) 9.95 (0.3917) d 2 9.972–9.987 (0.3926–0.3932) 9.95 (0.3917) intake/exhaust valves valve stem outer diameter intake 5.440–5.455 (0.2142–0.2148) 5.35 (0.2106) exhaust 5.426–5.444 (...

  • Page 97: Wm 90 Repair

    Wm 90 repair clearance data and limits table wc_tx000391gb.Fm 97 tappet stem outside diameter 7.960–7.975 (0.3134–0.3140) --- guide inside diameter 8.00–8.015 (0.3150–0.3140) --- tappet guide clearance 0.025–0.055 (0.0010–0.0022) --- valve seat angle (intake and exhaust) valve cutter angle (a) valve...

  • Page 98: Wm 90 Repair

    Clearance data and limits table wm 90 repair wc_tx000391gb.Fm 98 valve spring free length 26.7 (1.05) --- item standard mm (in.) limit mm (in.) wc_gr001947.

  • Page 99: Wm 90 Repair

    Wm 90 repair troubleshooting wc_tx000393gb.Fm 99 12. Troubleshooting 12.1 troubleshooting introduction if the engine shows any sign of malfunction, the cause should be determined immediately and the appropriate countermeasures should be taken to prevent the problem from worsening. This troubleshooti...

  • Page 100: Troubleshooting

    Troubleshooting wm 90 repair wc_tx000393gb.Fm 100 12.2.2 ignition system problems: check the following when experiencing a lack of spark. 12.2.2.1 wires of the ignition coil, spark plug, or contact breaker disconnected. 12.2.2.2 ignition coil damaged or shorted. 12.2.2.3 spark plug wire wet or soake...

  • Page 101: Wm 90 Repair

    Wm 90 repair troubleshooting wc_tx000393gb.Fm 101 12.2.5 engine stops: 12.2.5.1 fuel tank empty. Water, dirt, gum, etc. In gasoline. 12.2.5.2 vapor lock. Gasoline evaporating in the fuel lines due to overheating of the engine. 12.2.5.3 vapor lock in the fuel lines or carburetor due to using too vola...

  • Page 102: Troubleshooting

    Troubleshooting wm 90 repair wc_tx000393gb.Fm 102 notes.

  • Page 103: Threadlockers and Sealants

    Threadlockers and sealants threadlockers and sealants threadlocking adhesives and sealants are specified throughout this manual by a notation of “s” plus a number (s#) and should be used where indicated. Threadlocking compounds normally break down at temperatures above 175°c (350°f). If a screw or b...

  • Page 104: Threadlockers and Sealants

    Threadlockers and sealants threadlockers and sealants (continued) threadlocking adhesives and sealants are specified throughout this manual by a notation of “s” plus a number (s#) and should be used where indicated. Threadlocking compounds normally break down at temperatures above 175°c (350°f). If ...

  • Page 105: Torque Values

    Torque values torque values metric fasteners (din) torque values (based on bolt size and hardness) wrench size size nm ft.Lb. Nm ft.Lb. Nm ft.Lb. Metric inch metric inch m3 1.2 *11 1.6 *14 2.1 *19 5.5 7/32 2.5 – m4 2.9 *26 4.1 *36 4.9 *43 7 9/32 3 – m5 6.0 *53 8.5 6 10 7 8 5/16 4 – m6 10 7 14 10 17 ...

  • Page 106: Torque Values

    Torque values torque values (continued) inch fasteners (sae) size nm ft.Lb. Nm ft.Lb. Nm ft.Lb. Metric inch metric inch no.4 0.7 *6 1.0 *14 1.4 *12 5.5 1/4 – 3/32 no.6 1.4 *12 1.9 *17 2.4 *21 8 5/16 – 7/64 no.8 2.5 *22 3.5 *31 4.7 *42 9 11/32 – 9/64 no.10 3.6 *32 5.1 *45 6.8 *60 – 3/8 – 5/32 1/4 8.1...

  • Page 108

    Wacker construction equipment ag · preußenstraße 41 · d-80809 münchen · tel.: +49-(0)89-3 54 02 - 0 · fax: +49 - (0)89-3 54 02-3 90 wacker corporation · p.O. Box 9007 · menomonee falls, wi 53052-9007 · tel. : (262) 255-0500 · fax: (262) 255-0550 · tel. : (800) 770-0957 wacker asia pacific operations...