2-CYCLE GTS 120 ENGINE SERVICE MANUAL
Contents
1. 4 1 2 Fuel Tank Me eR EU Gee WE Oe ee ORS 11 2 Testing Compression 1 1222222 1 2 UE NAT a ae Engine Troubleshooting Chart 4 IV ENGINE REMOVAL DISASSEMBLY ASSEMBLY AND REPAIR INSTRUCTIONS IV 1 Engine Removal IV 1 Engine Dissassembly and Repair IV 1 Recoil Starter Repair 2 IV 1 Carburetor Repair secessit rea eee 2 Service Data Specifications IV 4 Maintenance Record IV 6 Maintenance Record sre cxx CEA p Aw NEEDLE Vd andes Te V ERR M a IV 7 GENERAL INFORMATION SAFETY INSTRUCTIONS Your rotary mower at the time of its manufacture meets the blade safety requirements of the Con sumer Product Safety Commissi2. In this condition fuel is drawn from the float bowl through the pilot system ports as well as the main discharge tube to achieve the proper starting mixture Figure 1 6 Pilot System Pilot Jet Pilot Air Fitting 2 YL i Wen Main Discharge Tube pm E 2 Float Bow Main Jet COLD START Figure 1 6 Fuel atomization becomes more efficient due to heat once the engine has reached normal operating temperature As a result the engine does not require the rich mixture it did for starting and the choke plate must be moved to the open position The engine speed is now regulated by the throttle plate In no load condi tions a small portion of the fuel may be drawn from the main discharge tube however the pri mary fuel supply is drawn from the pilot circuit 1 4 Air passing through the pilot jet from the pilot air fitting draws fuel out of the pilot jet orifice from the float bowl This fuel pre mixes with the incoming air then is discharged into the car buretor bore where the fuel becomes atomized Figure 1 7 M M M M Pilot System Pilot Air Fitting B Ne Throttle Plate Main Discharge Tube Float Bowl NO LOAD Figure 1 7 As the throttle plate is opened to compensate for loads the engine is being placed under the ma
3. 05mm 002 in Cylinder bore 0 cylinder bore is checked by measuring the cylinder liner at a total of six places using a cylinder gauge Two measurements 90 apart must be taken at the approximate A B and C elevations as shown Readings larger than the Third Port listed specifications indicate an excessively worn bore and the cylinder block must placed The cylinder liner is not a serviceable Cylinder Bore Diameter part of the engine 58 000 58 115mm 0 2 284 2 288 Piston to Cylinder Clearance The piston is cam ground into a slightly oval shape to compensate for heat distortion during operation The piston diameter is measured per pendicular to the wrist pin hole at a point above the piston skirt as indicated Subtract the piston measurement from the largest cylinder reading to determine the clearance Replace the cylinder block or the piston if the clearance is excessive Ped ig cuan 2 5mm 1 in Wrist Pin Wrist Pin Hole wrist and wrist pin hole must be properly fitted for efficient engine performance Measure the wrist pin and check the diameter of the piston holes to be no more than the oversize dimension indicated Wrist Pin Diameter Maximum Hole Diameter 11 955 12 005mm 472 473 in 050mm 002 in Oversize Piston Ring End Gap Use the piston to position the pist
4. 70 110 in Ib aon PER Recoil Mounting Capscrews M 6 _ Recoil Center Capscrew use thread lock compound 35 65 Kg Cm 40 75 in Ib 2 80 95 Kg Cm 70 110 in Ib Spark Plug M 14 70 105 Kg Cm 80 120 in tb Throttle Plate Capscrews M 6 80 95 Kg Cm 70 110 inb SPECIAL TOOLS LIST DESCRIPTION Flywheel 41 7650 Starter Cup Wrench 45 1390 Timing 41 7900 Spark ARDEN 41 7890 Continuity Eight iiit Rer Re exa eee 36 4050 2 Ree ed 42 2730 Ohmmeter Feeler Gauges ANEREN EE NN Spark Plug Gapping Compression Threebond 1104 Loctite 515 505 80 Loctite 242 Threebond 1342 505 76 Timing Dial Dial IndiCatoE ve ekz EE Ru Cylinder Gauge Set M Spark Plug Socket aser er trt es Coil Gauge 38 50mm 015 020 in Torque Wrench Torque Wren
5. Gas Oil Ratio 501 _ Gasoline Unleaded Regular Oil 2 cycle 1891249 Air Cleaner Two stage foam element Carburetor Mikuni BV 15 std main jet 80 High Altitude Jet 77 5 Governor Mechanical Flyweight 3000 150 Spark Arrester Muffler Optional PN 81 0200 Starter Recoil only _ Spark Plug NGK BPMR6A Spark Plug Gap 8 032 in Ignition Timing 22 2 BTDC Ignition Timing Piston Position _1 76 2 51 mm 069 099 BTDC Contact Point Gap 35 mm 014 _ Ignition Coil Air Gap 38 50 mm 015 020 in Float Height Setting Black Float IP The black float may be used on these engines as a replacement Part number 81 0970 2 FASTENER TORQUE SPECIFICATIONS ays Adapter Plate Housing Capscrews 3 8 16 UNC 2 9 4 6 Kg m 21 33 ft lb Blade Capscrew X 6 2 8 3 Kg m 45 60 ft lb Flywheel Nut M 10 ee ee 4 0 5 0 Kg m 29 36 ft lb Muffler Nuts M 8 90 120 Kg Cm 100 140 in Ib Air Cleaner Lock Nuts M 6 _ 60 90 Kg Cm 70 105 in Ib Adapter Plate Engine Capscrews 8 90 120 Kg Cm 100 140 in Ib Crankcase Capscrews M 6 80 95 Kg Cm 70 110 in Ib Shroud amp Muffler Capscrews M 6 _ 40 70 Kg Cm 45 80 20 Ignition Switch Mounting Capscrew M 6 80 115 Kg Cm 90 130 _ Air Cleaner Mounting Capscrew 5 17 26 Kg Cm 20 30 in Ib _ Recoil Starter Cup Capscrews M 6 80 95 Kg Cm
6. are present 2 Remove the four retaining capscrews from the recoil starter and lift the starter from the engine Disconnect the recoil rope from the rope handle stop for ease of handling RECOIL STARTER REPAIR A Remove the center capscrew from the recoil assembly and lift off the pawl re tainer Remove the center spring pawl and pawl spring Lift the rope pulley assembly from the recoil housing and remove the recoil spring and retainer Figure 4 1 B Replace all worn or damaged parts before reassembling Reassemble the recoil starter in reverse order Use Threebond 1342 or Loctite 242 on the threads of the center capscrew during reassembly and torque to 80 90Kg Cm 70 1 10 in Ib On installation there should be sufficient spring pretension to hold the recoil rope taut in the rope pulley NOTE Place a small amount of 2 grease on the recoil spring to prevent rust and corrosion Spring Rope Pulley Center Spring f ee Spring Retainer 5 2 Pawl 8 Center Capscrew Figure 4 1 3 Disconnect the fuel line from the carburetor Remove the fuel tank by lifting it from the mounting tabs of the blower housing 4 Remove the capscrew two nuts and lock washers which retain the muffler and remove the muffler from the engine The heat shield may also be removed from the muffler Dis card the muffler gasket and remove any gasket material remaining on the engine or
7. can be removed for inspection using a flat blade screwdriver IV 2 14 15 16 17 18 19 IMPORTANT NO OTHER PARTS ARE SERVICE ABLE DISASSEMBLY OF THE THROTTLE AND CHOKE PLATES IS NOT RECOMMENDED THE SCREWS ARE FACTORY TORQUED AND LOCKED IN PLACE IF NOT PROPERLY REAS SEMBLED THE SCREWS MAY LOOSEN AND CAUSE ENGINE DAMAGE D Reassemble the carburetor in reverse order The caburbetor and work area should be clean to prevent contamination entering the small orfices in the carbu retor body Remove the retaining capscrew lock washer anti scalp cup if applicable blade blade adapter and self propel components from the crankshaft Remove the four capscrews retaining the engine to the mower chassis and lift the engine from the mower To gain access to the components inside the crankcase remove the four capscrews re taining the engine to the mower adapter plate and remove the adapter plate from the engine Remove the six retaining capscrews holding the two halves of the crankcase together and separate the crankcase Remove the crankshaft and piston as an assembly Remove the seals bearing locat ing rings and bearings from each end of the crankshaft Slide the governor assembly from the crankshaft taking care not to lose the small locating pin for the governor fiy weight collar To remove the piston from the rod use needle nose pliers remove of the wrist pin retainers S
8. d Eo Sia S CP OUS 1 1 Exhaust System Jv E 1 1 Decarboning Cylinder Head A nm 1 2 Ignition Timing Model 47PZ2 Only ba 1 2 Ignition Timing Dial Indicator il 3 Contact Points and Condenser Model 47 22 Only cad DS hut geet 11 3 Ignition Coil Model 47PZ2 Only UU 1 3 Ignition Coil Models 47PD3 47PE4 47PF5 nea PEN 1 4 GOVEMOl voc vai Qr Opi E 1 4 Governor Operation island ite ir aa UD hee rece Tei WN ats eet 1 5 F elTank ARE 1 5 Vir E 1 6 pice 1 6 TROUBLESHOOTING AND TEST PROCEDURES ans 1 1 Preliminary Troubleshooting 112222 111 1 Spark Intensity qu HAN tebe pu Sees Cawsey 111 1 Engine Brake and Ignition Switch 111 1 Applications
9. required to expell the exhaust gases from the combustion chamber and to supply a fresh fuel mixture for the compression stroke The upward movement of the piston on the compression stroke creates a vacuum to draw fresh fuel into the crankcase In both instances a tightly sealed crankcase is the key to efficient performance The most likely places of leakage are at the governor shaft seal crankshaft seals and at the seam of the crank case halves The simplest means of detecting a crankcase leak is to check for wet oily deposits around the seal areas ENGINE TROUBLESHOOTING CHART The following troubleshooting chart fists the symptoms causes and remedies of common engine malfunctions Once the symptom has been determined systematically eliminate the possible causes until the actual cause is found POSSIBLE The possible causes have been arranged with the most easily inspected items to be checked listed first Utilizing the chart in this manner will lessen the amount of time required to repair the engine and limit the possibility of incorrectly diagnosing the cause of the difficulty SYMPTOMS _ Empty carb amp tank refill w fresh mix m CAUSES AN 4 EE Wrong type _ Install correct spark plug page 1 5 Spark Improper air gap X x Reset air gap 8mm 032 Plug Defective x eo spark plug Fouled x Replace spark plug _ Fuel Oil gas mix x Dirty stale Empty ca
10. the other testerleadtothis wire Figure 2 5 Turn the engine crankshaft its normal rotation counter clockwise as viewed from the output end The contact points should open as indicated by the timing tester when the pointer on the crankcase housing points to the center of the three marks on the flywheel casting If the timing is wrong the flywheel must be removed and the contact points regapped or replaced Models 47PD3 47PE4 and 47PF5 use solid state ignition systems and have their timing fixed at 22 Figure 2 5 IGNITION TIMING DIAL INDICATOR The ignition timing may be more accurately checked using a dial indicator Remove the spark plug wire and spark plug and insert the dial indica tor into the spark plug hole Rotate the engine crankshaft until the dial indicator registers the pis ton at top dead center and zero the dial Connect one lead of a timing tester to the engine frame A timing tester must be used An Ohmmeter or con tinuity light will not indicate the position of the con tact points Disconnect the wire at the ignition switch under the fuel tank and connect the other tester lead to this wire Figure 2 6 Slowly rotate the crankshaft clockwise as viewed from the out put end until the tester signals the contact points are opening If the tester signals between 1 76mm 069 in and 2 51 mm 099 in of piston travel as read on the dial indicator the engine is properly timed If the
11. timing is wrong the flywheel must be removed and the contact points regapped Figure 2 6 CONTACT POINTS AND CONDENSER MODEL 47 22 ONLY The contact points and condenser do wear out through use and their performance level is affected by dust moisture and corrosion Inspec tion of these components requires removal of the flywheel See Disassembly Instructions With the flywheel removed inspect for wear of the cam follower and burning or pitting of the contact points The surface of the contact points should have a grey frosted appearance if wearing normally If the contact points are cratered or have surface buildup they should be cleaned or replaced The contacts can be cleaned with an electrical sol vent and contact point sandpaper Ensure that all dust and dirt is removed after sanding Cratering of the points indicates the condenser may be faulty Verify the condition of the condenser through tests with an ignition analyzer If analyzer is not available the condenser must be considered faulty and should be replaced When Il 3 installing new or reconditioned contact points ensure that the wiring is routed through the channel in the crankcase housing and under the ignition coil FAILURE TO ROUTE THE WIRES PROPERLY MAY ALLOW THE WIRING TO CONTACT THE FLY WHEEL AND CAUSE A SHORT CIRCUIT Adjust the contact points to 35 01 4 in air gap using a feeler gauge with the cam follower on the high point of the ti
12. when there is adequate artificial light Cut slopes from side to side but avoid slopes when the grass is wet If possible mow when the grass is dry for best results 11 Keep face hands and feet away from the mower housing and cutter blade while the engine is running Stay behind the handle until the engine and all moving parts stop 12 During operation the grass defector or com plete bagging assembly must be installed on the mower 13 Stop the engine and wait for all moving parts to stop before removing the bag bagging assembly or unclogging the discharge chute If the chute must be unclogged pull the high tension wire from the spark plug to prevent the possiblity of accidental starting Use a stick to remove the obstruction 14 If a solid object is hit by the blade or if the mower vibrates abnormally stop the engine immediately Disconnect the high tension wire from the spark plug to prevent the possiblilty of accidental starting Then check the mower for possible damage bent blade an obstruction or loose parts Repair the mower before using it again 15 Stop the engine before adjusting the height of cut 16 If a gravel driveway road or path must be crossed stop the engine so loose sand and CUN rocks not thrown Before leaving the operator s position behind the handle stop the engine and wait for all moving parts to stop Do not walk in front of the mower while the engine is running
13. 2 CYCLE GTS 120 ENGINE SERVICE MANUAL Table of Contents Page 1 of 1 PREFACE GENERAL INFORMATION SAFETY INSTRUCTIONS MAINTENANCE MODEL AND SERIAL NUMBERS TWO CYCLE ENGINE THEORY AND OPERATION CARBURETOR THEORY AND OPERATION SPECIAL TOOLS LIST Il MAINTENANCE AIR CLEANER SPARK PLUG EXHAUST SYSTEM DECARBONING CYLINDER HEAD IGNITION TIMING MODEL 47PZ2 ONLY IGNITION TIMING DIAL INDICATOR CONTACT POINTS AND CONDENSER MODEL47PZ2 ONLY IGNITION COIL GOVERNOR GOVERNOR OPERATION FUEL TANK CARBURETOR STORAGE TROUBLESHOOTING AND TEST PROCEDURES PRELIMINARY TROUBLESHOOTING ENGINE BRAKE AND IGNITION SWITCH BBC APPLICATIONS FUEL TANK TESTING COMPRESSION CRANKCASE ENGINE TROUBLESHOOTING CHART IV ENGINE REMOVAL DISASSEMBLY ASSEMBLY AND REPAIR INSTRUCTIONS ENGINE REMOVAL ENGINE DISASSEMBLY AND REPAIR RECOIL STARTER REPAIR CARBURETOR REPAIR ENGINE ASSEMBLY AND REPAIR SERVICE DATA SPECIFICATIONS 2 cycle engine SERVICE UAL Toro Company Outdoor Products Division 8111 Lyndale Avenue South Minneapolis Minnesota 55420 PREFACE This service manual was written expressly for TORO Two Cycle Rotary Mowers All units with the model number 47 22 47PD3 47PE4 and 47PF5 engines have been taken into consideration The Toro Company has made every effort to make this service manual a useful tool for the service and maintenance of your TORO Rotary Mower Engine To ass
14. Dis connect the high tension wire from the spark plug if the mower will be unattended Do not touch any part of the engine while it is running or shortly after it is stopped because the engine will be hot enough to cause a burn 17 18 Muffler is extremely hot Keep children and pets away MAINTENANCE 19 Before the mower is serviced or adjusted stop the engine and remove the key from the switch Disonnect the high tension wire from the spark plug to prevent the possibility of accidental starting To assure the mower is in safe operating condition keep all nuts bolts and screws tight Assure the blade capscrew is tightened to the proper torque If major repairs are ever needed or if assis tance is desired contact an Authorized TORO Service Dealer If the mower must be tipped when it is serviced or adjusted drain the gasoline from the fuel tank If a guard safety device or safety decal is damaged replace the defective part s be fore operating the mower To reduce potential fire hazards assure the mower is free of excessive grease grass leaves and accumulations of dirt The grass bag must always be in good con dition therefore check it before each use to assure the bag is not torn or deteriorated Always replace a defective grass bag Allow the engine to cool before storing the mower in any enclosure such as a garage or storage shed Do not store the mower near any open flame or where gasolin
15. Figure 2 12 Connect the return spring to the center hole in the governor spring bracket The center hole should goveron the engine speed at the recom mended 3000 RPM The top hole will raise the engine speed 150 RPM and the bottom hole will lower the engine speed 150 RPM Engine speed can be verified using a tachometer such as listed in the Special Tools Section See page 1 6 GOVERNOR OPERATION Refer to Figure 2 13 As load on the engine in creases the engine speed will start to decrease the engine slows down the centrifugal force of the flyweights 1 will decrease The governor return spring 4 will cause the governor collar 2 to move in direction A The governor arm 3 will also move in direction A causing the throttle to open until the centrifugal force of the flyweights are in balance with the governor return spring As the load on the engine decreases the engine will speed up caus ing the flyweights to move out forcing the governor collar in direction B The collar will act against the governor arm moving it in direction B and also moving the throttle in direction The engine speed will drop until once again the flyweight and return spring are in balance Figure 2 13 Figure 2 13 Models 47PD3 47 4 47PF5 are equipped with variable throttles The linkage is described in Figure 2 14 A mounting boss was added to the casting of the engine to accommodate the throttle linkage assembly
16. The boss does not exist on model 47PZ2 engines therefore the variable throt tle linkage will not retrofit Model 47PF5 engines will include a weld stud on the governor linkage for ease of reassembly See Figure 2 15 Governor Spring Figure 2 14 0 Weld Stud Figure 2 15 FUEL TANK CAUTION The gasoline the fuel tank is explosive Always drain or fill tank outdoors away from fire and flame Do not smoke when fuel vapors are present For the engine and carburetor to function properly the fuel supply must be clean Stale dirty and im properly mixed fuel will cause starting and running difficulties To assure a clean fuel supply the fuel tank may be removed and flushed with fresh fuel See Disassembly Instruction A non replaceable sintered bronze fuel filter is inset into the fuel tank outlet In some cases the filter can be cleaned by back flushing with solvent or by blowing low pres sure compressed air through the fitting on the bottom of the fuel tank Commercial engines have a replaceable inline fuel filter located between the fuel tank and carburetor The replacement fuel filter is Toro Part Number 56 6360 Figure 2 16 Period ically inspect the vent in the fuel tank cap Remove any foreign materials which may plug the vent The gasket inside the cap may be removed to permit further cleaning of the vent area Fuel Cap Vent Mol Gasket D Fuel Filter motded into tan
17. age 111 3 Spark Intensity The ignition system can be checked for spark in tensity using the spark tester listed in the Special Tools Section of this manual Figure 3 1 Figure 3 1 11 1 1 Pull off the spark plug connector and remove the spark plug 2 Inspect the spark plug for wear carbon deposits and damage See Maintenance Section Replace the plug if damaged burnt or fouled 3 Check for the correct spark plug gap and adjust if necessary to 8 mm 032 in by bending the outer electrode Do not pry against the inner electrode or the insulator may be damaged 4 Attach the spark tester as shown and verify the tester gap is set at 4 2 mm 166 in 5 Pull the starter and observe for spark THE SPARK MAY BE DIFFICULT TO SEE IN WELL LIGHTED AREAS CAUTION Do not test for spark where gasoline has been spilled or inflammable vapors may exist A fire could result 6 If spark is viewed refer to the trouble shooting chart Page 111 4 ENGINE BRAKE AND IGNITION SWITCH As a safety measure the engine is designed to stop within three seconds after the control bar is released Release of the control bar grounds the magneto through the ignition switch to prevent ignition and allows the spring activated brake pad to engage the flywheel The engine brake and ignition switch are con trolled by one common control cable activated by the control bar on the mower handle To start the engine the control b
18. ar Insert the small locating pin into the crankshaft and slide the flywheel collar into position Position the fly weights on the lip of the governor collar and locate the control shaft between the collar and the crankshaft assembly See Figure 2 13 and 4 2 Lubricate the crankshaft bearings with two cycle oil and install onto either end of the crankshaft Insert the bearing locating rings into the slots of the crankcase housing to locate the bearings and crankshaft in position Remove burrs from either end ofthe crankshaft and slide seals into position To prevent seal damage on installation use a small amount of 2 grease on the inside diameter of the seal Both seals should be installed with the lip fac Figure 4 2 5 Assure both halves of the crankcase are clean and free of grease and old sealant Apply a thin uniform amount of Threebond 1104 or Loc tite 515 sealant to the mating surfaces and position of the crankcase halves together 6 There are three different size capscrews on the model 47PZ2 to hold the crankcase halves together The capscrews on the 47PD3 47PE4 and 47PF5 are all the same length Starting on the governor control shaft side install the two medium sized capscrews at either end Install one short capscrew and governor spring bracket in the center hole Install the other two remaining short capscrews into the other side in the center hole and the hole nearest the large end of the crankshaft Insta
19. ar is raised and held against the handle This pulls the brake pad away from the flywheel and simultaneously de presses the plunger on the ignition switch THE ENGINE BRAKE SYSTEM SHOULD BE MAINTAINED IN PROPER WORKING CONDI TION OR INJURY MAY RESULT To troubleshoot the engine brake and ignition switch 1 Remove the fuel tank for ease of inspection See Disassembly Instructions page 1 2 Ensure that the brake spring forces the brake pad against the flywheel when the control bar is in the STOP position and that the pad clears the flywheel when the control bar is in the START position 3 Disconnect the wire leading to the ignition switch and connect a continuity tester to the switch wire and engine frame Figure 3 2 with the control bar in the STOP position there should be continuity through the switch With the control bar in the START position there should be NO continuity through the switch 4 Adjust the cable or replace the switch which ever is necessary to assure that the switch and brake assembly are functioning properly Figure 3 2 BBC APPLICATIONS Engines equipped with a Blade Brake Clutch BBC mechanism Models 47PD3 47PE4 and 47PF5 with serial numbers that start with 2 are fitted with an ignition kill switch that is mounted on the throttle linkage See Figure 3 3 The ignition wire is connected to the kill switch terminal When the lift bail is released the BBC mechan
20. brake pad on the engine Release the control bar and connect the ignition switch wire 47PZ2 and zone start models only IMPORTANT CHECK FOR PROPER OPER ATION OF THE IGNITION SWITCH AND BRAKE ASSEMBLY See Troubleshooting Section page 111 1 Place the blower housing on the engine attach with one capscrew in the front and another in the rear NOTE USE CAUTION IN ROUTING THE HIGH TENSION WIRE SO THAT IT DOES NOT BECOME PINCHED BETWEEN THE BLOWER HOUSING AND THE ENGINE Place the muffler and muffler gasket over the engine studs Install the through boit nuts and lock washers on the muffler and tighten to the recommended torque Connect the choke cable to the carburetor and clamp the cable in place on the blower housing Install the air cleaner housing to the carburetor mounting studs using the ap propriate nuts Install the through bolt and tighten the bolt and nuts to the recom mended torque Position the filter element in place and install the air cleaner cover En sure the cover snaps firmly in place Slide the fuel tank into position and connect the fuel line to the carburetor Attach the recoil assembly using the four capscrews required and route the starter rope through the handle stop on the mower handle Install the spark plug and attach the high tension wire Measure at A 38 1mm 1 5 in both ends Total alignment difference between largest and smallest readings must be less than
21. ch Magnetic Dial Indicator Stand 1 MAINTENANCE CAUTION To reduce poten tial accidents never perform an adjustment maintenance proce dure while the engine is running Pull the high tension wire off the spark plug to prevent an accidental start AIR CLEANER The air cleaner must be maintained properly to ensure foreign materials cannot damage the engine or foul the carburetor The air cleaner element must be cleaned after every 50 hours of engine operation or more frequently if the engine is operated in dusty or dirty conditions Lift the cover tabs securing the air cleaner cover to the housing and remove the cover Figure 2 1 Clean the inside of the cover and housing if it is dirty Air Cleaner Housing Figure 2 1 if the air cleaner element is dirty remove it from the housing for cleaning DO NOT ALLOW DIRT TO ENTER BEHIND THE ELEMENT OR ENGINE DAMAGE WILL RESULT Wash the element in a solution of liquid detergent and water Squeeze the element to remove the dirt Do not twist the element or the element may tear Press the element in a dry rag until it is completely dry Saturate the element with approximately five teaspoons of SAE 30 oil and squeeze to distribute the oil thoroughly The element must be dampened with oil to function properly Replace the ele
22. e fumes may be ignited by a spark Do not overspeed the engine by changing the governor settings Recommended speed of the engine is 3000 rpm To assure safety and accuracy have an Authorized TORO Service Dealer check the engine speed with a tachometer At the time of manufacture the mower con formed to the safety standards in effect for 20 21 22 23 24 25 26 2T 28 rotary mowers To assure optimum perfor mance and continued safety certification of the mower use genuine TORO replacement parts and accessories Replacement parts and accessories made by other manufac turers may result in nonconformance wm the safety standards MODEL AND SERIAL NUMBERS The TORO Two Cycle Rotary Mower has two sets of identification numbers There is a model and serial number to identify the engine and a model and serial number to identify the chassis The engine identification numbers are stamped into the blower housing behind the air cleaner Model 47PF5 engines built for 1986 have the engine identification numbers stamped in the blower housing above the spark plug Engine models 47 4 and 47PF5 have serial nubmers that start with the number 1 2 or 3 The number 1 indicates a zone start application The number 2 indicates BBC application and the number 3 Indicates commercial application The chassis identification numbers are located on adecalonthe back of the mower housing between the rear wheels In any cor
23. he capscrews retaining the contact point cover and lift the cover from the engine Remove the small nut retaining the electrical wires to the contact point assembly Remove the two ignition coil hold down screws and lift the ignition coil and wire harness from the engine 11 Remove the two screws holding the points and condenser in place and lift the points and condenser from the engine Remove the flywheel key from the crankshaft and slide the timing cam from the engine There is a small locating pin for the cam Take care so that this pin is not lost 12 Loosen the clamping bolt on the governor lever and pry the clamping section of the lever apart with a screwdriver Remove the lever control rod and springs from the engine 13 Disconnect the choke cable from the car buretor and slide the carburetor spacer and gaskets from the mounting studs IMPORTANT DO NOT REMOVE THE CHOKE SHAFT SCREW OR THE THREADS MAY BE COME STRIPPED CARBURETOR REPAIR A Drain the fuel from the carburetor bowl by removing the bowl nut washer and bowl The bowl seal be replaced using seal pick if fuel leakage is noted on the carburetor bowl B One end of the float pivot pin is purposely deformed to lock the pin into the casting legs Visually determine which end is deformed and drive the pin from the opposite end Remove the pivot pin float needle valve and spring retainer from the assembly C The main jet and the pilot circuit jet
24. in discharge tube becomes the main source of fuel Opening the throttle plate increases the flow of air through the venturi and strengthens the low pressure area at the main discharge tube Fuel discharge increases at the main discharge tube as it decreases from the pilot system Air is drawn from the air correction jet through holes along the length of the main discharge tube This pre mixes air with the fuel before it enters the carburetor bore for more efficient atomizing of the fuel Figure 1 8 Pitot System SLL MMW 2 n Choke Plate 2 A ZAN N N N ff inlet Needle Tube ELS 5 VAS d Float Float Bowl UNDER LOAD Figure 1 8 ENGINE SPECIFICATIONS Model 47 22 2 cycle single cylinder piston ported air cooled N Rotation viewed from output end Counter clockwise Displacement 121 7 38 cu in m Bore 58mm 228in Stroke 46mm 1 81in Crankshaft 24 9 mm 98 in forged steel Rated Output 3 5 Hp 3600 RPM Torque 73 kg m 5 28 ft lb 3000 RPM Compression Ratio 6 1 8 4 kps cm 1 20 psi to E 10 5 kps cm 150 psi
25. ism will stopthe blade and leave the engine running stop the engine the throttle control is brought to the stop position which will bring the governor spring lever in contact with the kill switch grounding the ignition and stopping the engine Spring Lover a Kill Switch 9 9 j insulator Bracket Figure 3 3 2 FUEL TANK If the engine stalls or will not start there may be a fuel restriction or blockage The fuel cap con tains a vent which if plugged will fuel from entering the carburetor 1 Remove the fuel cap and inspect the vent Clean if necessary 2 Visually inspect the bottom of the fuel tank for dirt or other contaminants 3 If dirt water or other contaminants are present the tank should be flushed with a small amount of fresh fuel This is most easily accomplished when the fuel tank is removed See Disassembly Instructions page IV 1 2 CAUTION gasoline in the fuel tank is explosive Always drain or fill tank outdoors away from fire and flame Do not smoke when fuel vapors are present 4 Toensure the fuel filter is not plugged remove the fuel lines and check the fuel filter for ease of fuel flow Insome instances the filter may be cleaned by back flushing with solvent or low pressure compressed air NOTE The bronze sintered filter in the fuel tank i is not replaceable however the remote mounted in
26. k Inline Fuel Filter Part No 56 6360 Figure 2 16 1 5 CARBURETOR The non adjustable carburetor has a number of small orifices which control the flow of fuel and air to obtain the proper combustable mixtures If stale or dirty fuel enters the carburetor deposits can form causing adverse changes to this combustable mixture To clean the carburetor it must first be removed and disassembled See Disassembly Instructions Soak all metal parts in carburetor cleaner to remove deposits THE BOWL SEAL FLOAT AND NEEDLE VALVE SHOULD NOT BE CLEANED WITH CARBURE TOR CLEANER OR DAMAGE MAY RESULT Replace any damaged or questionable compo nents before reassembly Figure 2 17 Pilot Jet Main Jet Engine Model 47PZ2 Carburetor Standard Main Jet 80 Toro Part No 81 1040 Optional High a titude Main Jet 277 5 Toro Part No 81 1050 Figure 2 17 Carburetors used on models 47PD3 47 4 and 47PF5 see Figure 2 18 use a metal choke shaft with a plastic bushing an atmospheric vent tube and an alcohol resistant float The floats used on 47PZ2 carburetors should be replaced with a 81 0970 float This float is blackandis equipped with a metal hinge Correct float height is 17 5mm 11 16 in The standard main jet is a number 76 3 part number 81 1940 There is a lean number 72 5 main jet part number 81 2340 available for high altitude conditions The standard main jet on 47PZ2 carburetors is a number 80 part n
27. lide the wrist pin out of the piston far enough to allow the piston to be removed from the connecting rod The needle bearing may be removed from the connecting rod however there are no further serviceable parts on the crank shaft assembly IMPORTANT THE THREE PIECE CRANK SHAFT IS ASSEMBLED AT THE FACTORY TO PRECISION TOLERANCES ATTEMPT ING TO DISASSEMBLE THE CRANKSHAFT FURTHER WILL RESULT IN CRANKSHAFT DAMAGE The wrist pin and piston rings may be re moved from the piston for replacement The top ring is made of cast iron with a chrome plating on the outside diameter IMPORTANT USE CAUTION WHEN RE MOVING THE RINGS OVERSTRETCHING THE RINGS WILL RESULT IN DURING ENGINE REASSEMBLY Remove the governor shaft E ring and flat washer and slide the governor shaft out of the crankcase Use seal pick to remove the governor shaft seal NOTE The cylinder contains a cast iron sleeve however this sleeve is not replaceable The purpose of the sleeve retainer ring is to assist the manufacturing process and hold the cast iron sleeve in place to limit engine damage should the sleeve loosen during operation Engine Assembly And Repair NOTE Before attempting to reassemble the engine refer to the Service Data Specifications page 4 and replace all parts which are outside the recom mended values 1 Ensure there are no burrs on the governor shaft which could cause seal damage and position the gover
28. line fuel filter found on commercial engines may be replaced using Toro Part Number 56 6360 See Figure 2 16 TESTING COMPRESSION compression test of the engine provide vital information on the general condition of the working parts within the engine This test will indicate a worn cylinder piston or rings and generally determine whether the engine is re pairable or if it should be replaced 1 Remove the spark plug and install a com pression gauge into the spark plug hole Figure 3 4 Figure 3 4 2 Pull the starter rope rapidly several times until the compression reading on the gauge stabilizes Ifthe compression reading is below 6 5 kps cm 92 psi cylinder piston or ring damage should be suspected A new engine should have 8 4 kps cm 120 psi 10 5 kps cm 150 psi An engine with low compression must be dis assembled and inspected for damage of the internal components See Disassembly Instruc tions Check all components to the specifica tions listed in the Service Data Section of this manual Replace all parts which fall outside of these specificatons The engine contains a cast iron cylinder liner which is not replaceable Special factory processes are required to install this liner 11 3 CRANKCASE The engine relies on a tightly sealed crankcase in order to function properly The downward movement of the piston causes the crankcase to be pressurized This pressure is
29. ll the long capscrew in the remaining hole Torque all capscrews evenly 80 95 Kg Cm 70 1 10 in Ib See Figure 4 3 Position the engine mower Short Governor Governor Spring Bracket 47PZ2 Only Torque Capscrews to 80 95 Kg Cm 70 110 in Ib Figure 4 3 10 adapter plate with the dimple facing the spark plug end Install the four retaining capscrews and torque to the proper specification Install the ignition cam and locating pin to the flywheel end of the crankshaft Install the con denser and points in position Rotate the crank shaft until the cam follower is on the high point of the cam Adjust the point gap using a feeler gauge of the appropriate size to set the airgap at 35 mm 014 in A7PZ2 engine only Install the ignition coil loosely on the mount ing posts Connect the double lead to the contact point assembly 47PZ2 engine only making sure the wires are routed between the ignition coil mounting posts The single lead should be routed along side of the crankcase housing through the hole in the casting The ignition coil air gap setting will be adjusted later Place the gasket spacer and the second gas ket over the mounting studs of the carburetor SeeFigure 2 18 for correct gasket and spacer placement Slide the carburetor onto the mounting studs Assemble the governor con trol lever linkage and springs to the governor shaft and the carbure
30. mber where they help expel the burnt gases and charge the chamber for the following piston stroke Figure 1 4 Exhaust Port Open Fresh Fuel Change Third Port Closed Figure 1 4 CARBURETOR THEORY AND OPERATION Theory The carburetor receives fuel from the tank and mixes it with air in the right proportions to provide a highly combustible mixture to the engine 7 As the piston moves up on the compression stroke a partial vacuum is created within the engine crankcase causing the greater atmos pheric pressure to force air to flow through the carburetor into the cylinder The velocity of the air increases as it flows through the carburetor venturi and the air pressure is reduced at this point to less than atmospheric pressure The differences of pressure in the venturi of the carburetor causes atmospheric pressure to push raw fuel from the float bowl into the air stream where it breaks up into a fine spray or becomes atomized and mixes with the air stream Figure 1 5 Atmospheric Pressure a Carburetor LL Suc RD Bore To Engine Float Bowl Figure 1 5 Operation When starting the engine an extra rich mixture is required The choke plate is closed by the opera tor to provide an approximate 8 1 ratio of fuel to air for this rich mixture Closing the choke plate further reduces the air pressure area in the venturi to increase the fuel drawn into the car buretor bore
31. ment and install the cover Assure that the cover snaps in place and is seated securely on the air cleaner housing IMPORTANT DO NOT OPERATE THE ENGINE WITHOUT AN AIR CLEANER ELEMENT OR EXTREME ENGINE WEAR AND DAMAGE WILL RESULT SPARK PLUG Many times an inspection of the spark plug can determine whether the engine is functioning properly A spark plug which is functioning normally will show slight electrode wear with brown or greyish tan deposits Oil fouled and black carbon fouled plugs are caused by a rich carburetor mixture weak spark or improper gasoline to oil mixture Excessively worn elec trodes or a blistered insulator indicate spark plug overheating Look for incorrect ignition timing cooling fins clogged with debris improper gaso line to oil mixture and dirty carburetor any of which may cause this trouble IMPORTANT A CRACKED FOULED OR DIRTY SPARK PLUG MUST BE REPLACED DO NOT SAND BLAST SCRAPE OR CLEAN THE ELEC TRODES GRIT MAY EVENTUALLY RELEASE FROM THE PLUG AND CAUSE ENGINE DAM AGE The recommended spark plus is an NGK BPMR6A or Champion RCJ8Y See Page 1 5 The air gap between the electrodes should be set at 8 mm O32 in Figure 2 2 Since the air gap increases gradually through use the spark plug should be removed after every 25 hours of opera tion to check its condition Clean the area around the spark plug to prevent foreign material from falling into the cylinder Install
32. ming cam Figure 2 7 Check the tim ing using either method previously described It may be necessary to readjust the contact point gap to obtain the timing specification 35mm 014 max Contact Point Assembly Condenser Cam Follower Figure 2 7 IGNITION COIL Whenever the flywheel is exposed the ignition coil condition and air gap should be checked Inspect the ignition coil fora cracked casing loose laminations damaged wires and overheating The ignition coil air gap is 38 50 mm 015 020 in A non metallic flexible gauge such as shown in the Special Tools Section should be used To adjust rotate the flywheel magnets away from the igni tion coil and loosen the two ignition coil retaining capscrews Insert the gauge between the coil laminations and the flywheel Figure 2 8 Tighten the retaining capscrews to hold the adjustment Figure 2 8 The ignition coil contains two separate windings inside the coil casing Figure 2 9 Use an Ohm meter to check the resistance levels of each wind ing To check the primary winding disconnect the ignition switch wire and connect the positive lead of the Ohmmeter to the ignition coil lead Connect the negative leadtothe engine frame ground The primary winding resistance is 82 1 1 ohms Rx1 scale To checkthe secondary winding disconnect the high tension wire at the spark plug Connect the positive lead of the Ohmmeter to the high te
33. muffler 5 Lift the retaining tabs of the air cleaner cover and remove the cover and filter element Remove the capscrew and two locknuts retaining the air cleaner housing and lift the housing from the engine 6 Remove the remaining three capscrews from the blower housing and lift the blower hous ing from the engine 7 Cage the spring activated engine brake by compressing and retaining the control bar against the operating handle Remove the capscrew holding the ignition switch and brake assembly in place Disconnect the ignition switch from the electrical lead and remove the switch from the brake assembly Slowly lower the contro bar to disengage the brake The brake assembly may now be disconnected from the control cable for repair 8 Use a starter cup wrench as shown in the Special Tools List to hold the starter cup while loosening the flywheel nut Hold the flywheel by hand and remove the three maining capscrews retaining the starter cup to the flywheel It may be necessary to insert a screwdriver through the starter cup to hold the flywheel should the capscrews be tremely tight IMPORTANT DO NOT DEFORM THE STARTER CUP OR STARTER ENGAGE MENT DIFFICULTY MAY RESULT 9 Use the flywheel puller listed in the Special Tools Section to pull the flywheel from the crankshaft IMPORTANT DO NOT PRY ON THE FLY WHEEL CASTING OR STRIKE THE CRANK SHAFT OR DAMAGE WILL RESULT 10 Remove t
34. n sion wire Connect the negative lead to the engine frame ground The secondary coil resistance should be 5800 7940 ohms 1000 scale The ignition coil must be replaced if the resistance levels are incorrect Ignition Switch Wire High Tension Wire Primary Coil 82 1 1 ohms R x 1 scale Secondary Coil 5800 7940 ohms R x 1000 scale Ground Model 47PZ2 Figure 2 9 The ignition coil used on models 47PD3 47 4 and 47PF5 consists of the main coil high tension wire and ignition kill wire See Figure 2 10 Testing of the coil may be completed with a Graham Lee ignition tester model number 31 SMXH In structions for testing are included with the tester High Tension Wire Figure 2 10 1 4 GOVERNOR The governor linkage is factory preset to regu late the engine speed at 3000 150 RPM Check the adjustment of the governor if the engine is suspected of improper speed To gain access to the governor linkage removal of the air cleaner is recommended See Disassembly Instructions Before adjusting the governor inspect the control linkage for bent broken and worn parts Loosen the governor arm clamping bolt and use a screwdriver to spread the gover nor arm clamp Figure 2 11 Figure 2 11 Adjust the governor by holding the governor lever to the right while turning the governor shaft to the right Hold the adjustment and tighten clamp Figure 2 12 the
35. ngine quickly 4 Keep everyone especially children and pets away from the area of operation Remove sticks stones wire any other debris that might be picked up and thrown by the blade 5 TAMPERING WITH OR DEFEATING A SAFETY DEVICE OR COMPONENT WHICH RESULTS NONCONFORMANCE WITH SAFETY STANDARD MAY RESULT IN PER SONAL INJURY Each time before operating the mower check for damage or abnormal wear If a safety device shield or decal is defective or damaged repair or replace it before operation is commenced 6 Wear long pants and substantial shoes Do not operate the mower while wearing sandals tennis shoes sneakers or shorts Do not wear loose fitting clothing that could get caught in moving parts 7 If long grass will be cut set the height of cut in the highest position After mowing rein spect the area and remove all debris Then lower the height of cut and mow the grass again 8 Since gasoline is highly flammable handle it carefully i A Use an approved gasoline container B Do not fill the fuel tank when the engine is hot or running C Do not smoke while handling gasoline D Fill the fuel tank outdoors and up to about one half inch from the top of the tank not the filler neck E Wipe up any spilled gasoline While Operating 9 Cutting the grass with a rotary mower de mands attention Always maintain secure footing balance and control 10 Cut the grass during the daytime or
36. nor shaft through the hole in the crankcase casting Use a liberal amount of 2 grease and install the governor shaft seal with the lip towards the inside of the crankcase Position the flat washer on the governor shaft against the shaft seal and install the E ring 2 Install the two piston rings onto the piston The chrome surfaced ring should be posi tioned at the top of the piston There is a small letter R stamped on the top side of each piston ring This letter should face the top of the piston If the piston ring is put in upside down it will not seat properly in the ring groove Lubricate the wrist pin needle bearing with two cycle oil and insert into the connecting rod Position the piston over the connecting rod and insert the wrist pin through the piston needle bearing and pis ton rod Insert the spring retainers to lock the wrist pin in place IMPORTANT THE ARROW CAST INTO THE TOP OF THE PISTON MUST FACE THE EXHAUST PORT WHEN ASSEMBLED 3 Lubricate the moving parts and friction sur faces of the crankshaft and piston with two cycle oil Rotate the piston rings until the ring gap aligns with the locating studs before attempting to push the piston into the cylinder Insert the crankshaft and piston assembly into the cylinder IMPORTANT ASSURE THE ARROW ON TOP OF THE PISTON FACES EXHAUST PORT WHEN ASSEMBLED 4 Lubricate the large end of the crankshaft with two cycle oil and install the sliding governor coll
37. on ring at the most worn area of the cylinder liner The most wear will occur where the rings normally travel during operation or the area of largest diameter as measured earlier Use a feeler gauge to check the gap between the ends of the piston ring 027 Piston Ring Side Clearance Decarbon the piston rings and grooves Hold the piston rings into the grooves and use a feeler gauge between the bottom of each ring and groove to determine clearance IMPORTANT The letter R must face the top of the piston 03 15mm 001 006 ETUR A gt gt TT IV 5 MAINTENANCE RECORD E E EL EE Ey 12 Low 4 x3 MEN BEN HII i E II IGNITION 7 d OPERATING AIR SPARK EXHAUST HOURS CLEANER PLUG SYSTEM DATE IV 6 MAINTENANCE RECORD I PERFORMED BY OTHER IGNITION EXHAUST SYSTEM OPERATING AIR SPARK HOURS CLEANER PLUG DATE E Tm N IV
38. ons Safety Stan dard for Walk Behind Power Lawn Mowers A representative sample was tested and verified by an independent laboratory for compliance with the B71 1 1980 Specifications of the American National Standards Institute However improper use or maintenance by the operator or owner can still result in injury To reduce the potential for injury follow these safety instructions This machine is equipped with a blade brake which is designed to stop the blade within 3 seconds when the control lever is released Check to be sure the control and brake function correctly before each use of the mower Repair any defective or damaged safety components before operation is commenced To further reduce the possibility of injury always stop the engine before leaving the operator s position A This safety symbol means WARNING or CAUTION PERSONAL SAFETY INSTRUCTION Read the instruction because it has to do with safety Failure to comply with the instruction may result in personal injury Before Operating 1 Operate your mower only after reading the Operators Manual A replacement manual is available by sending the complete model and serial number to The Toro Company 8111 Lyndale Avenue South Minneapolis Minnesota 55420 Attn Publications 2 Never allow children to operate the mower or adults to operate the mower without proper instructions 3 Become familiar with the controls and know how to stop the e
39. r in solvent to remove wet oil deposits Allow to air dry or dry with compressed air Remove the muffler heat shield and tap the muffler body with a plastic hammer to loosen the carbon deposits Blow all the loose carbon from the muffler using com pressed air Install the muffler using a new gasket and attach it with proper fasteners tightened to the correct torque See page l 5 DECARBONING CYLINDER HEAD If the exhaust ports and muffler show signs of ex cessive carbon buildup it may be necessary to decarbon the cylinder head Toaccomplish this the entire engine must be disassembled to allow access into the combustion chamber See Dis assembly Instructions Page IV 1 Remove the carbon deposits from the piston and the cylinder chamber using a wooden stick TAKE CARE NOT TO SCRATCH THE PISTON OR CYLINDER CHAMBER AND DO NOT USE A METAL TOOL TO REMOVE THE DEPOSITS IGNITION TIMING MODEL 47PZ2 ONLY To check the timing it is necessary to remove the air cleaner to view the flywheel See Disassembly Instructions The flywheel has a group of three raised marks on its outer edge The center mark corresponds to 22 BTDC and the others represent the tolerance of plus or minus 2 Connectone lead of the timing teste to the engine frame ground A timing tester must be used An Ohmmeter or conti nuity light will not indicate the position of the con tact points Disconnect the wire at the ignition switch under the fuel tank and connect
40. rb amp tank refill w fresh mix x Vent plugged x Clean or replace cap Fuel System Filter plugged Back flush filter or replace tank Line restriction x Check lines for restriction Air Dirty filter Clean or replace filter Cleaner Excess oil X Squeeze excess oil from filter Crankcase Poor seal Reseal crankcase and replace seals Misadjusted Readjust See page 11 4 Governor Broken spring Replace spring Worn linkage x Replace worn parts Misadjusted Readjust refer to page III 2 Ignition Switch Faulty wiring Repairorreplace __ Defective Replace ignition switch Exhaust Muffler plugged Clean or replace See page 1 System Ports plugged Clean all exhaust ports Choke plate adj x Check linkage and cable adjustment Throttle Check linkage and governor Carburetor Clogged jets X Clean carburetor jets incl pilot jet Diagnose and replace worn parts Diagnose and replace broken parts Worn needle x Bowl float Starter Jammed broken x Misadjusted x a Faulty wiring x oil Defective Broken Flywheel Magnets weak Sheared key Points Misadjusted Burnt corroded Condenser Faulty wining Defective Clogged fins Worn parts
41. respondence concerning the mower supply the model and serial numbers to assure that the correct information and replacement parts are obtained Genuine TORO replacement parts may be ordered through your local TORO Aute rized Service Dealer TWO CYCLE ENGINE THEORY AND OPERATION Theory Two cycle engines have special advantages which make their use more practical in certain applications Two cycle engines are lightweight with an excellent power to weight ratio and can be operated in any position They are also notably easy to maintain and service because of their uncomplicated design The TORO Two Cycle Engine used on the TORO Rotary Mowers is a third port loop scavenged design This design name describes the path of the fuel air mixture into the crankcase and com bustion chamber and the exhausting of spent gases In a loop scavenge engine a high pressure area is created in the crankcase by the downward movement of the piston Pressurized fuel air mixture rushes into the combustion chamber through the intake ports and is directed toward the cylinder head This fresh mixture then strikes the cylinder head and loops down forcing burnt gases in the combustion chamber out through the exhaust ports third port design engine has the carburetor mounted on the side of the cylinder The passage from the carburetor into the crankcase is called the third port All ports within the engine are opened and closed by the pi
42. ston skirt as the piston moves up and down within the cylinder Operation The piston closes all engine ports as it moves toward the combustion chamber Figure 1 1 The moving piston creates a high pressure in the com bustion Chamber and a partial vacuum in the crankcase intake Ports Closed Compression Partial Vacuum Intake Ports Closed Third Port Closed Figure 1 1 At a point slightly before top dead center of the pistontravel the sparkfrom the plug ignites the fuel air mixture Figure 1 2 Also at this time the third port opens allowing the fresh fuel air mixture to rush into the crankcase to equalize the partial vacuum Intake Ports Closed Ignition Figure 1 2 When the fuel is ignited by the spark plug the expanding gases from the burning fuel in the com bustion chamber force the piston downthe cylinder closing the third port and increasing the pressure inthe crankcase At a point approaching the bottom of the stroke the exhaust port opens and the burnt gases begin to be expelled from the combustion chamber Figure 1 3 Intake Ports Closed Exhaust Port Opening Pressure Building Up Third Port Closed Figure 1 3 At a point of piston travel slightly before bottom dead center BBDO the fuel transfer ports on the sides of the cylinder walls are uncovered and the compressed fuel air mixture in the crankcase is allowed to enter the combustion cha
43. t be caused by the envi ronment Clean the dirt and chaff from the outside ofthe cylinder cylinder head fins and blower hous ing The air cleaner assembly should be serviced as mentioned earlier in this section For lawn mower storage instructions refer to the Operators Manual TROUBLESHOOTING AND TEST PROCEDURES Generally all gasoline powered products require some form of service or repair during their life time The amount of time and expense involved in repairing a product can be greatly impacted by the amount of time required to initially deter mine the cause of the difficulty Therefore it is recommended to make these preliminary checks before proceeding to secondary troubleshooting procedures PRELIMINARY TROUBLESHOOTING Ignition System 1 Check the ignition switch and wiring 2 Ensure the spark plug is the correct type 3 Check the spark plug for the correct gap damaged and excessively carboned or burnt electrodes 4 Check the spark intensity Fuel System 1 Check the choke position and controls 2 Check the throttle if so equipped and gover nor mechanism 3 Ensure the fuel is fresh clean and of the proper gas oil mixture 4 Check the fuel filter Air Cleaner 1 Check for housing and element damage 2 Check for dirty element 3 Check for too much or too little oil in the element Compression 1 Check the cylinder compression Refer to page 111 2 Crankcase 1 Ensure the crankcase is 255188 Refer to p
44. the spark plug with the metal gasket and tighten to 70 105 Kg Cm 80 120 in Ib 8mm 032 in T ao Figure 2 2 EXHAUST SYSTEM One important part of the maintenance for all two cycle engines is the cleaning or decarboning of the exhaust system This is done to assure the unobstructed flow of exhaust gases and carbon particles from the combustion chamber A se verely carboned muffler spark arrester screen or exhaust port will cause poor starting and low power output To de carbon the exhaust system remove the muffler from the engine by removing the two retaining nuts and the through boit Figure 2 3 Figure 2 3 Check the cylinder exhaust port If necessary remove the carbon deposits from the port using a wooden stick Also clean the small hole next to the exhaust port This hole acts as a compression relief to lessen the force required to start the engine If plugged the recoil starter will be hard to pull Figure 2 4 IMPORTANT WHEN REMOVING CARBON DE POSITS ROTATE THE CRANKSHAFT TO CLOSE THE EXHAUST PORT WITH THE PIS TON THIS WILL PREVENT LOOSE CARBON DEPOSITS FROM FALLING INTO THE CYLIN DER TAKE CARE NOT TO SCRATCH THE PISTON AND DO NOT USE A METAL TOOL TO REMOVE THE DEPOSITS Figure 2 4 Before installing the muffler check for cracks and leaks Inspect the inlet and outlet for carbon buildup Remove excessive deposits with a scraping tool and soak the muffle
45. tor throttle plate Move the governor shaft to the right and rotate the governor shaft to the right Tighten the clamp bolt to hold the adjustment Install the contact point cover 47PZ2 engine only flywheel key and flywheel to the crank shaft Install the starter cup with the capscrews andtorque to 80 90 Kg Cm 70 110 in Ib Use 11 the starter cup wrench to hold the flywheel from turning and tighten the retaining nut on the end of crankshaft to 4 5 Kg m 29 36 ft Ib Use the air gap gauge listed in the Special Tools Section and adjust the air gap between the flywheel and ignition coil laminations to 5 mm 020 in maximum Attach the engine to the mower chassis and install the blade components to the engine SERVICE DATA SPECIFICATIONS Crankshaft Alignment Place the magnetic V blocks under the crank shaft bearing support area To level the crank shaft shims must be added under the magnetic block at the flywheel end Rotate the crank shaft with the dial indicator positioned as shown and note the indicator fluctuations Take readings on both ends of the crankshaft IV 4 12 13 14 15 16 17 m Ea a I t rr crankshaft The blade retaining capscrew should be tightened to 6 2 8 3 Kg m 45 60 ft lb Cage the engine brake spring by lifting the control bar into the handle and retaining it in place Install the ignition switch brake assem bly and
46. umber 81 1040 with a high alti tude 77 5 jet part number 81 1050 option Models 47PD3 47PE4 and 47PF5 are also equipped with a heat deflector and insulator as shown in Figure 2 18 Model 47PZ2 was built with out insulators or heat deflectors This model may be fitted with a heat shield kit number 81 2210 to prevent hot restart problems Engine Model 47PD3 47 4 47PF5 Carburetor Standard Main Jet 76 3 Part No 81 1940 High Altitude Main Jet 72 5 Toro Part No 81 2340 Figure 2 18 STORAGE Drain the gasoline from the fuel tank After the gas oline is drained start the engine and let it run until all fuel is expended Move the recoil starter a num ber of times to assure all fuel is expended All gas oline must be removed to prevent gumlike varnish deposits from forming in the fuel system Pull the high tension wire off the spark plug Clean the area around the plug to prevent dirt from entering the cylinder when the plug is removed Remove the plug from the cylinder head and pour two tea spoons of two cycle oil into the spark plug hole Pull the recoil starter handle slowly to distribute the oil inside of the cylinder Install the spark plug and tighten to the recommended torque DO NOT INSTALL THE HIGH TENSION WIRE ON THE SPARK PLUG Pull the recoil starter slowly until a positive resistance is felt This will ensure the com bustion chamber is sealed by the piston to prevent any damage which migh
47. ure proper and effective performance you are urged to read this manual carefully The purpose of this manual is to provide the Service Dealer with working lt guidelines of maintenance troubleshooting test and overhaul procedures The Toro Company reserves the right to change product specifications or this manual without notice The Toro Company Service Department COPYRIGHT ALL RIGHTS RESERVED The Toro Company 1986 MINNEAPOLIS MN 55420 U S A TABLE OF CONTENTS TOPIC PAGE 1 GENERAL INFORMATION I 1 Safety Instructions MU RU VK 1 1 Maintenance criss TERAPIA DIETS 1 2 Model and Serial Numbers E E FHF2 Two Cycle Engine Theory and Operation m 1 2 Carburetor Theory and Operation MOM buscada te ara a dne uh 1 4 Engine Specifications 1 5 Fastener Torque Specifications ba ee 1 5 Special TOOIS 1 6 II MAINTENANCE 1 1 1 1 Spark Plug
48. x Broken parts x gt Carbon build up _ Replace needle _ Replace cracked bowl float Repair or replace starter _ Readijust See page Ill 2 X Repair or replace _ Replace ignition coil Replace flywheel Replace flywheel _ EE Inspect keyway and replace key X _Readjust See 2 2 Clean or replace points Repair replace Replace condenser _ Remove debris from engine housing _Decarbon IV ENGINE REMOVAL DISASSEMBLY ASSEMBLY AND REPAIR INSTRUCTIONS ENGINE REMOVAL To remove the engine from the mower the air cleaner housing recoil assembly and fuel tank must first be removed to disconnect the control cables Remove the retaining capscrew lock washer blade blade adapter and self propel components below the mower deck from the engine crankshaft Remove the four capscrews that retain the engine to the mower chassis and remove the engine from the mower The engine can then be placed in a support fixture for repair Most common repairs however can be accom plished with the engine in place on the mower chassis Use the following procedures to dis assemble the engine on the mower chassis ENGINE DISASSEMBLY AND REPAIR 1 Remove the high tension wire from the spark plug and drain the fuel from the fuel tank A CAUTION The gasoline in the fuel tank is explosive Always drain or fill tank outdoors away from fire and flame Do not smoke when fuel vapors
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