OHV GTS 140 ENGINE SERVICE MANUAL Table of Contents – Page 1 of 3 PREFACE 1. GENERAL INFORMATION SAFETY INSTRUCTIONS GENERAL SERVICE SAFETY INSTRUCTIONS MODEL AND SERIAL NUMBERS SPECIFICATIONS SERVICE DATA CARBURETOR FASTENER TORQUE SPECIFICATION SPECIAL TOOLS 2. MAINTENANCE AIR CLEANER CHANGING OIL SPARK PLUG VALVE LASH GOVERNOR AND THROTTLE LINKAGE IGNITION FUEL SYSTEM CARBURETOR STORAGE 3.
OHV GTS 140 ENGINE SERVICE MANUAL Table of Contents – Page 2 of 3 3. TROUBLESHOOTING AND TEST PROCEDURES - Continued TESTING--ELECTRIC STARTER IF THE MOTOR TURNS: IF THE MOTOR DOES NOT TURN: TESTING--ALTERNATOR REMOVAL--ELECTRIC STARTER INSTALLATION--ELECTRIC STARTER REMOVAL--ALTERNATOR INSTALLATION--ALTERNATOR RECOIL STARTER REMOVAL AND DISASSEMBLY--RECOIL STARTER REPAIR--RECOIL STARTER ROPE REPLACEMENT SPRING REPLACEMENT REASSEMBLY 4.
OHV GTS 140 ENGINE SERVICE MANUAL Table of Contents – Page 3 of 3 4.
PREFACE This Service and Overhaul Manualwas written expressly for theT O R 0 model VMFS and VMG6 OverheadValve Engine. The Toro Company has made every effort to make this service manual a useful and lasting addition to every service facility. To assure proper and effective service, and to provide optimum performance for the life of the engine, you are urged to read this manual carefully.
TABLE OF CONTENTS PAGE 1 GENERAL INFORMATION Safety General Model Specifications Service Special e 2 MAINTENANCE Air Consumer Commercial Air Cleaner Maintenance ir Changing Spark Plug ValveLash 7 Governor Ignition Fuel Carburetor Storage 17 3 TROUBLESHOOTING AND TEST PROCEDURES Preliminary Troubleshooting Carburetor Removal Service Reassembly Gas Cap Disassembly 14 Service Reassembly Fuel & Filter Disassembly Service Reassembly Ignition Testing Removal Installation Electric & Alternator Testing Testin
Muffler Electric Starter Alternator Ignition Oil Fill Tube Throttle Control and Carburetor Flywheel Breather Cylinder Head Assembly Valves Oil Pump Crankcase Governor Assembly Camshaft Compression Release Piston and Connecting Rod Inspection and Reconditioning Crankshaft Connecting Rod Piston Cylinder Piston Rings Valves Reassembly31 Piston.
ments, keep clearof the PTO shaft, cutting blades and other moving parts. 7. Do not overspeed the engine by changing thegovernorsettings.Maximumengine speed with no load is listed in the engine specifications on page 2. 8. The engine must be stopped before checking the oil or adding oil to the crankcase. 9. Do not touch the engine muffler or guard while the engine is running or soon after it has stopped.These areas couldbehot enough to cause a burn.
SPECIFICATIONS OHV x 44 mm (2.52 in x 1.73 in) 141 cc (8.7 cu. in) HP/3600 rpm 0.83 kg-m (6.00 ft-lb)/2700 rpm BPR6ES (0.028 in 0.032 in) (.015-,020) Engine type Air cooled 4 cycle, gasoline, Bore and stroke .64 mm Displacement Maximum output 4 Maximum torque Spark plug NGK Spark plug gap .0.7 mm 0.8 mm Ignition coil air gap.. .38-50 mm Fuel Unleaded regular Fuel tank capacity .1.2 Oil.. Oil capacity Ignition system Electronic transistorized ignition Ignition timing degree Starting system. .
mit SERVICE DATA DATA UNIT ITEM mm (in! Crankshaft diameter Upper crankshaft: 21.960 -21.980 (0.8646 0.8654) Lower crankshaft: 24.959 0.9835) 24.980 (0.9826 ____- Crankshaft Limit deflection mm (in) 0.05 (0.0020) Wear limit on cylinder bore mm (in) 0.100 (0.0039) mm (in) 63.960 Limit mm (in) 63.915 (2.5163) STD mm (in) 0.025 mm (in) 0.120 (0.0047) Piston pin hole diameter mm (in) 15.006 15.014 (0.5904 0.5911) Piston pin diameter mm (in) 14.995 15.000 (0.5904 0.
SERVICE DATA (Continued) ITEM Valve guide to valve stem clearance UNIT Intake (STD) mm(in) 0.025 Intake (Limit) mm (in) 0.080 (0.0032) mm (in) 0.045 mm (in) 0.100 (0.0039) mm (in) 0.3 (0.0118) mm (in) 32.0 mm (in) 31 .O (1.2205) mm (in) 30.517 Exhaust (STD) Exhaust (Limit) Valve guide oversize Valve spring free length DATA Limit 0.052 (0.0010 0.0020) 0.072 (0.0018 34.0 (1.2598 0.0028) 1.3386) 30.577 (1.2015 1.2038) CARBURETOR ITEM UNIT DATA MlKUNl BV 18-13 TYPE 82.
SPECIAL TOOLS @ Adaptor Valve guide reamer Reamer handle Expandable pilot T-handle wrench Cutter head A 50-9410* 50-9480* Valve guide remover & 81-4840 81-4850 81-4860 50-9500* Cutter head 60" Rotor remover 81-4830 41-7650 81-4870 installer 81-4880 *These tools are also used on the edger and generator engines. Figure 1-3 All fasteners on theOHV engine are metric. The standard set of tools will require the following: 3/8 in.
2. MAINTENANCE AIR CLEANER The consumer air cleaner should be serviced every 25 hours of engineuse. The commercial air cleaner is of a two part design: the foam pre-cleaner should be serviced every 25 hours and the paper element every 50 hours. More frequent service for both air cleaners may be required in dusty or dirty conditions. Consumer Air Cleaner Maintenance 1. Stop the engine and pull the high tension wire off the spark plug. 2. Cleanloosedebrisfromtheaircleaner body. 3.
SPARK PLUG Remove the spark plug after every 25 operating hours and check its condition. Usean NGK BPR6ES spark plug or its equivalent. The air gap is ,813 mm (.032 in.). 1. Stop the engine and remove the spark plug wire. 2. Clean the area around the spark plug and remove the plug. 3. Replaceacracked,fouledordirtyspark plug. Do notsandblast,scrapeorclean electrodes because engine damage could result from grit entering the cylinder. 4. Set the air gap to .813 mm (.032 in.).See Fig. 2-6.
IGNITION The OHV engine uses asolidstateignition system with timing fixedat 25 degrees BTDC 2 degrees at 3000 RPM. Ignition timing is not adjustable.However,ignitiontimingmay change if a blade impact has occurred and the flywheelkey hassheared. Theenginemay continue to runwithadegradation in performance. Under these conditions the timing will advance, makingstartingandrunning difficult. The coil to flywheel air gap set is at .38 mm (.015 in.). FUEL SYSTEM The fuel tank has a capacityof 1.
inlet needle with stainless a steel tip. The needle is replaceable. The carburetor is also fitted with a bowl drain screw that can be used to drain fuel out of the bowl after the tank is drained. See Fig. 2-12. Openthescrewanddrainthefuelintoa suitable container. CARBURETOR The OHV engine is equipped with a Mikuni BV 18-13 float bowl type Carburetor. The standard mainjet is anumber 82.5. Thisnumberis stampedinthebaseofthejet.Theonly adjustment on the carburetor is the pilotsystem pilot screw.
led 3. TROUBLESHOOTING AND TEST PROCEDURES This section has been divided into the troubleshooting and service of individual systems. To determine what system needs to be evaluated, some preliminary troubleshooting is necessary. These are checks that can be made with littlen oor disassembly and would normally be made with the customer or owner present.
TROUBLESHOOTING CHART The information gathered in preliminary troubleshooting can now be used with the following troubleshooting chart to determine individual systems to be serviced. _ . _ _ _ ~ ~ _ _ _ ~ _ _ _ PROBLEM POSSIBLE CAUSES ~ ~ _ _ _ _ _ _ _ _ _ _~__. 1. Throttle not in CHOKE position. 2. Gas tank is empty. 3. Air cleaner element is dirty. 4. Spark plug is loose. Engine does not St; 5. Spark plug wire is loose or disconnected from spark plug. 6. Spark plug gap is incorrect. 7.
CARBURETOR rod to allow it to beunhookedafterthe carburetor has been removed. Removal - Carburetor 1. Drain and remove the fuel tank; refer to Fuel System page 8. The fuel tank is held in place with two screws and is removedby pulling it straight up. Drain the carburetor fuel bowl anddisconnectthefuelhosefromthe carburetor. See Fig. 3-1. Figure 3-3 5. The bowl of the carburetor may be removed byunscrewingtheretainingnutonthe bottom of the bowl.See Fig. 3-4.
7. The pilot jet may be removed next. The pilot Service Carburetor jet is a #40 and can be cleaned or replaced. The metallic body of the carburetor may be Fuel flows through the small opening in the cleaned in carburetor cleaner. Plastic parts may end of the jet and air enters through the be damaged by some carburetor cleaners. holes in the side. The opening on the top Carburetor passages may be cleaned out with has no function as it is plugged. compressed air. Thepilotscrewcontrolsairinthepilot circuit.
Figure 3-9 Figure 3-11 Service 6. Remount the bowl and gasket. 7. Mount the gaskets and spacer on the studs. 1. The tank should provide a free gravity flow of fuel to the carburetor (the tankis higher The correct sequence is described in Fig. than the carburetor).If a free flow of fuel is 3-10. not evident (the engineis starving for fuel) loosenthecapand see if fuelflow is re-established. is not 2. If thefuelflowimproves,thecap venting.
2. Whenthethrottlecontrol is inthe“run” position,thethrottle lever shouldmove away from the ground tang.See Fig. 3-13. Reassembly 1. Install a new filter, if necessary. 2. Mount the fuel tank using two spacers and two screws. 3.Routethefuelhosebehindthegovernor arm. 4. Connect the hose to the carburetor. IGNITION Testing Spark Intensity The ignition system can be checked for spark intensityusingasparktester,partnumber 41-7890. 1. Pull off the plug connector and remove the spark plug. 2.
Removal Ignition 1. Drain the fuel tank.Refer to Fuel System on page 8. 2. Remove the air cleaner assembly. Refer to Air Cleaner Removal on page 12. 3. Remove the shrouding, including one screw retaining the muffler guard. See Fig. 3-18. Note: It is not necessary to remove the recoil starter unless it is to be serviced. Figure 3-15 2. With the control bail tensioned (run position), the brake pad is pulled away from the flywheel and the brake lever is rotated away from the ground tang. See Fig. 3-16.
6. If removal of the brake assembly and switch isnecessary,removethetworetaining screws. See Fig. 3-21. Figure 3-22 2. Remove the spark plug wire and disconnect the starter motor plug. 3. Apply 12 volts direct to the starter motor terminals. See Fig. 3-23. Figure 3-21 Installation Ignition 1. Mount the brake assembly or throttle assembly. 2. Install the ignition coil. Mount a wire retainer on either the right or left side of the coil, depending on the brake system used. Refer to Fig. 3-19. 3.
Testing Alternator Batterydoesnotchargeduringmower operation: 1. Check battery connections and alternator connections to make sure they are complete and secure. Check the connection points at the battery, alternator wire, key switch and all ground connections. 2. Measurethealternatoroutputwiththe engine at3000RPM. Withthebattery connected, alternator output should 13.2 be voltsDC.Thevoltagecanbemeasured between the red wire on the key switch and the black ground wire. 7. 3.
RECOIL STARTER All OHV engines, including electric start, are equippedwithrecoilstarters.Recoilstarter service is performed as follows: Retainer Pinion Stop Pinion Removal and Disassembly Recoil Starter 1. Remove the four screws retaining the starter to the blower housing. See Fig. 3-29. Note the orientationof the recoil rope for proper reassembly. Figure 3-27 Removal Alternator 2, 3underRemoval 1.Followsteps1, Figure 3-29 Ignition on page 16. 2. Remove the two screws retaining the alter2.
4. Thefrictionspring is directlyunderneath the starter pawl guide. The starter pawl is alsovisible. See Fig. 3-32.Removethe friction spring. Figure 3-35 Figure 3-32 8. The detensioned recoil spring will be capturedinthebottomoftherecoilpulley. Carefully lift the pulley and recoil spring free of the recoil housing.See Fig. 3-36. 5. Remove the shaft spacer. See. Fig. 3-33. Figure 3-33 6. Remove the nylon washer that is installed under the spacer and spring. See Fig. 3-34.
7. Re-install the recoil starter. Repair Recoil Starter Themostlikelycomponentsontherecoil starter to require repair are the coil spring and Spring Replacement starter rope. 1. Followstepsonethroughnineunder “Recoil Starter Removal and Disassembly” on page 19. 2. Carefullyremovethebrokenspringto CAUTION: Wearsafety preventrapidexpansionofthespring. glasses and use extreme care CAUTION: Wear safetyglassesanduse when working with the recoil spring. If extreme care to prevent injury.
4. ENGINE DISASSEMBLY, INSPECTION AND REASSEMBLY DISASSEMBLY Recoil Starter 1 . Removethefourscrewsretainingthe starter. 2. If the recoil starter must be disassembled, refer to Recoil Starter Removal and Repair on page 19-20. Fuel Tank 1 . Drain the tank per instructions on page 8. 2. Drainthecarburetorperinstructionson page 9. 3. Disconnect the fuel hose. Figure 4-2 4. Remove the two screws retaining the fuel tank. Alternator 5. Lift the fuel tank off the engine. 1.
5. Examine the condition of the flywheel taper, keyway and crankshaft key and taper. See Fig. 4-7. Figure 4-4 Throttle Control and Carburetor 1. Refer to “Removal-Carburetor’’ on page 12. 2. Refer to disassembly steps5 , 6 , 7 , 8 on page 12-13 if further carburetor service is necessary. Flywheel 1. Use a screwdriver through the starter cup to hold the flywheel in place. 2. Use a 19 mm socket to remove the flywheel nut. See Fig. 4-5. Figure 4-7 Breather 1.
3. The reed retainer and reed must be mounted “up” as seen in Fig. 4-9. Cylinder Head Assembly 1. Remove the four screws retaining thevalve cover. See Fig. 4-10. Don’t lose thewashers under each screw. Figure 4-12 Figure 4-10 2. Iftheheadassemblyistobecompletely torn down, remove each valve rocker arm. This step is not essential to the removal of the cylinder head. Hold the adjusting nut with a14 mm wrench and loosen the jam nut with a10 mm wrench.See Fig. 4-1 1.
Oil Pump 1. Turn the engine upside down and remove thethreescrewsretainingtheoilpump cover. Use a 10 mm wrench or socket.See Fig. 4-18. PCOVER Figure 4-15 Valves 1. The valve keepers may be removed by hand. Support the bottom of the valve with your fingers and push down and back with your thumbs on the keeper.See Fig. 4-16. Figure 4-18 2. Remove the oil pump cover and examine the condition of the“0” ring. The oil pump is a two-piece gerotor type oil pump driven by the camshaft. See Fig. 4-19.
2. Note the position of the two thrust washers. Crankcase Refer to Fig. 4-23. One washer is located 1. Removethe seven screwsretainingthe under the plunger and one is located under sumpassemblytotheblock. When the the governor assembly. sump is pulled off the crankshaft, take care Camshaft not to cut the seal. See Fig. 4-21. 1. The camshaft drives both the governor and the oil pump.Refer to Fig. 4-22. 2. The witness marks on the cam gear and crank gear can be seen in Fig. 4-24.
5. Pull the cam followers out of theengine. New parts are identical and may be placed ineitheropening.Usedpartsshouldbe installed in the original holes to maintain wear patterns. I’ FLYWEIGHT Figure 4-29 Figure 4-27 6. If necessary,thegovernorshaftmaybe removedbyunseatingtheretainingring and pulling the shaft out of the block. See Fig. 4-28. There are noseals or “0” rings in the block or on the shaft. FLYWEIGHT MOVEMENT Figure 4-30 Piston and Connecting Rod 1.
lower diameter of the crankshaft is 24.959 24.980 (.9826 .9835). 2. Thepistonandcrankshaftmaynowbe removed from the cylinder. See Fig. 4-32. Rod Journal Diameter 25.99-26mm (1.023-1.024 in.) Figure 4-34 Figure 4-32 3. Remove the piston rings. The bottom ring is for oil control, the second ring is cast iron for quick seating and the top is ring chrome plated for long wear. “N”. 4. Theringsaremarkedwiththeletter The “N” should face up on correct installation. See Fig. 4-33. Connecting Rod 1.
Piston 1. Measure the outside diameterof the piston. The piston should measure 63.960 63.975 mm (2.51812.5187 in.). If thepiston measures less than 63.915 mm (2.5163 in.) replace it. See Fig. 4-37. Cylinder Bore Measurement Piston Diameter Figure 4-39 The amount of wear is the difference between the largest and smallest measurements. 3. The wear limit is .1 mm (.0039 in.). 63.960-63.975 mm (2.5181-2.5187) Piston Rings 1. Measurethepistonringclearanceinthe piston ring groove.See Fig. 4-40. Clearance .
Valve Seat Angles Valve Stem Diameter 15” Exhaust 5.440-5.455 (.2142-.2148 in.) Figure 4-41 45’ 60” Figure 4-43 to valve guide 3. Calculatethe valvestem clearancewearlimit.Subtractthe valve stem diameter from the valve guide I.D. If these limits are exceeded, the valves and valve guides must be replaced. Intakeclearancelimit .08 mm (.0032 in.) Exhaust clearance limit ,100 mm (.0039 in .) See Valve Guide Replacement on page 30. 4.
2. diameter of the hole after reaming will be 9.300-9.315mm (.3661-.3667 in.) on both intake and exhaust. 3. C. Use the valve guide installer, part number 81-4880, to drive in the new oversize valve guides. part number 81-3830. Drive the guides in from valve the cover side of the head. When properly installed, there 27.5 mm (1.08 in.)clearance willbe between the end of thevalve guide and the gasket surface of the head.See Fig. 4-45. Theletter “N” on each piston ring should face toward the topof the piston.
Governor Assembly 1. Lubricate and install the thrust washer on the flyweight shaft. Lubricate and install the flyweight assembly.Push it down on the shaft until it snaps in place. 2. Placeasmallamount ofgrease onthe governor plunger and thrust washer. Install them on the flyweight shaft.See Fig. 4-52. Figure 4-49 Camshaft and Followers 1. Install the cam followers. Theyare both the same, it makes no difference in which of the two openings they are installed. Oil before you insert them. See Fig. 4-50.
4. Insert the four head bolts and torque to 1.8 -2.8 kg-m (13 20 ft-lb). See Fig. 4-55. Figure 4-53 Valves 1. Lubricatethe valve stemsand installthe valves in the head. 2. The valveheadsare markedintakeand exhaust. The intakevalve is mounted in the largediameteropeningandtheexhaust valve ismountedinthesmalldiameter opening. NOTE: It is possible to insert the valves in the wrong opening they but will not seal. 3. Install the valve springs and keepers.
Figure 4-57 Breather 1. Install the reed plate assembly. 2. Make sure there is a gasket underneath and on top of the reed plate. 3. Install the cover plate. Use twomm 6 screws that are 12 mm long. If longer screws are used, the block may be damaged. Torque the screws to .4 .7 kg-m (3.0 5.0 ft-lbs). See Fig. 4-58. Figure 4-59 2. Installthethrottlecontrolarm(governor arm) on the governor shaft do not tighten the retaining nutat this time.See Fig. 4-60. Figure 4-58 Flywheel 1.Inspectandinstallthekey.
Alternator Coil and Starter Motor 1. If theengine is electricstart,mountthe alternator coil on its bosses as shown in Fig. 4-64. Figure 4-61 Oil Fill Tube 1. Install “0” ring fully into the groove on the oil fill tube.See Fig. 4-62. Figure 4-64 r \ 2. Theairgaponthealternatorcoil is not adjustable. 3. Be sure to route the alternator wire through the rubber grommet. Take care not to pinch the wire behind the starter motor. 4. Mount the starter motor on its bosses with two screws. Figure 4-62 2.
Muffler and CoolingShroud 2. Mount the air cleaner as shown in Fig. 3-2. 1. Mount the muffler shroud with two screws Fuel Tank only. 2. Mount the cooling shroud and secure it with 1. Routethefuelhosebehindthegovernor arm. threescrews. Do notinstallthescrew through the oil fill tube at this time. 2. Connect the fuel hose to the carburetor. 3. Install the third screw through the muffler 3. Mount the fuel tank with two screws. shroud and cooling shroud. Recoil Starter Air Cleaner 1 .
