Resi dent i alPr oduct s TORO®Twi nCyl i nderEngi ne Ser vi ceManual I ssued:Febr uar y2017
ABOUT THIS MANUAL This service manual was written expressly for Toro® service technicians. The Toro Company has made every effort to make the information in this manual complete and correct. Basic shop safety knowledge and mechanical/electrical skills are assumed. The Table of Contents lists the systems and the related topics covered in this manual. We are hopeful that you will find this manual a valuable addition to your service shop.
TABLE OF CONTENTS General Service Information..................................................................................................1-1 Air Filter System.....................................................................................................................2-1 Two Barrel Carburetor and Fuel System..............................................................................3-1 Control Plate (Throttle and Choke).........................................................................
General GENERAL SERVICE INFORMATION Table of Contents Safety..................................................................................................................................... 1-2 Service Reminders............................................................................................................... 1-3 Engine Model/Serial Number Location.............................................................................. 1-3 Specifications................................................
GENERAL SERVICE INFORMATION This symbol means WARNING or PERSONAL SAFETY INSTRUCTION – read the instruction because it has to do with your safety. Failure to comply with the instruction may result in personal injury or even death. This manual is intended as a service and repair manual only. The safety instructions provided herein are for troubleshooting, service, and repair of the Toro Twin Cylinder Engine.
General GENERAL SERVICE INFORMATION Service Reminders: 1. Only use genuine Toro parts and lubrication products. 2. Always install new gaskets, o-rings and seals when reassembling. 3. Always torque fasteners to specification and follow recommended sequences. 4. Always lubricate friction components with clean engine oil or engine assembly lube when assembling the engine. Engine Model/Serial Number Location The engine model and serial numbers are engraved into the crankcase (Figure 1).
GENERAL SERVICE INFORMATION Specifications Engine General Specifications Engine Name 2P77F Type V-Twin Cylinder, 4-Stroke, Forced Air Cooling, OHV Bore X Stroke 77 x 76 mm Displacement 708 cc Compression Ratio 8.7:1 Lubrication Oil Pump with Oil Filter Starting Electric Rotation Counter Clockwise (from P.T.O. side) Ignition System Transistorized Magneto Ignition Air Cleaner Paper with Foam Wrap Fuel Type Unleaded Gasoline, 87 Octane Oil Capacity 80 oz. (2.
General GENERAL SERVICE INFORMATION Engine Fastener Torque Specifications (Engine 2P77F) (Cont.) Intake Manifold Bolts 89 in - lbs. (10 Nm) Oil Drain Hose Cleat Bolts 62 in - lbs.(7 Nm) Oil Drain Plug 19 ft - lbs.(26 Nm) Oil Filter 106 in - lbs. (12 Nm) Oil Pump Cover Bolts 89 in - lbs. (10 Nm) Oil Screen Cover Bolts 89 in - lbs. (10 Nm) Muffler Nuts 146 in - lbs.(17 Nm) Rocker Arm Pivot Lock Nuts 124 in - lbs.(14 Nm) Rocker Arm Studs 22 ft - lbs. (30 Nm) Spark Plugs 21 ft - lbs. (28.
GENERAL SERVICE INFORMATION Engine Component Specifications Part Engine Cylinder Head Cylinder Piston Piston Pin Piston Rings Connecting Rod Crankshaft Valve 1-6 Table of Contents Item Standard Service Limit Operating (Top) RPM 3300 ± 100 RPM - Idle RPM 1800 ± 150 RPM - Warpage - 0.00197 in. (0.05 mm) Sleeve Taper/Out of Round (Inside Diameter) 3.0315 - 3.0319 in. (77 - 77.01 mm) 3.0354 in. (77.10 mm) Skirt Outside Diameter 3.620 - 3.621 in. (76.965 - 76.975 mm) 3.0219 in. (76.
General GENERAL SERVICE INFORMATION Engine Component Specifications (Cont.) Part Item Standard Service Limit Inside Diameter (Intake, Exhaust) 0.2598 - 0.2604 in. (6.60 - 6.615 mm) 0.2624 in. (6.665 mm) Stem to Guide Clearance (Intake) 0.00079 - 0.00197 in. (0.02 - 0.05 mm) 0.0059 in. (0.15 mm) Stem to Guide Clearance (Exhaust) 0.00157 - 0.00275 in. (0.04 - 0.07 mm) 0.00669 in. (0.17 mm) Valve Seat Seat Width 0.02756 - 0.03149 in. (0.7 - 0.8 mm) 0.05118 in. (1.
GENERAL SERVICE INFORMATION Tool Requirements: 1) Digital Multi-Meter 2) Cylinder Leak Down Tester 3) Two Spark Testers 4) Carburetor Pressure Tester 5) Feeler Gauge 6) Flywheel Puller 7) Valve Seat Cutter Kit 8) Valve Lapping Tool 9) Metric Tap & Die Set 10) Spark Plug Wrench 11) Foot Pound and Inch Pound Torque Wrench 12) Tachometer (Digital Preferred) 13) Metric Wrench and Socket Set 14) 7/32 in. or 15/64 in.
General GENERAL SERVICE INFORMATION Troubleshooting Problem Possible Causes Engine Cranks but will NOT Air filter restricted Start Engine Hard Starting/Poor Running Next Step...
GENERAL SERVICE INFORMATION Troubleshooting (Cont.) Problem Possible Causes Next Step... Engine Hard Starting/Poor Running (Cont.
General GENERAL SERVICE INFORMATION Maintenance Maintenance Schedule Each Use Top Shroud Clean Engine Oil Oil Level First month or 5 hours Change Air Cleaner Foam Element Clean Air Cleaner Paper Element Clean Oil Filter Replace Fuel Filter Replace Spark Plug Replace Every 3 months or 25 hours Every 6 months or 50 hours * Change Change Check-Adjust Combustion Chamber Clean Remove blower shroud and clean Compressed air Fuel Hose Every 2 years or 200 hours * * * ** Check-Adjust V
AIR FILTER SYSTEM Introduction........................................................................................................................... 2-2 Component Description........................................................................................................ 2-2 Air Filter System.................................................................................................................... 2-5 Removal..............................................................................
AIR FILTER SYSTEM Introduction: The air intake system is a unique air filtration system containing a heavy duty air filter door, dual element air filter, self-cleaning air box and cast aluminum air filter manifold (Figure 1). Figure 1 Component Description Air Filter Door: Attaches to the blower shroud, heavy duty hinge design and no tools required to maintain the air filter. Locks air filter into position by simply closing the door and the air filter will slide into place (Figure 2).
AIR FILTER SYSTEM Component Description (Cont.) Air Filter Air Filter: Dual element, foam pre-filter fits over paper element. Two outlets fit snugly onto the air filter manifold ports (Figure 3). Figure 3 Air Box: The chamber is designed to keep debris away from the filter, angled floor away from engine and three holes in blower shroud allows air from the flywheel fan to blow debris past the filter (Figure 4).
AIR FILTER SYSTEM Component Description (Cont.) Air Filter Manifold: Constructed of cast aluminum for durability. Filter mount ports are angled to prevent debris from entering when servicing the filter. The ports are machined to provide proper seal to air filter. The manifold has vent ports for the fuel tank vent and the crankcase breather vent (Figure 5). B A C Figure 5 A. Crankcase Breather B. Fuel Tank Vent C.
AIR FILTER SYSTEM Removal Air Filter 1. Open the air filter door. 2. Rotate the filter upward by lifting at door hinge to remove from air filter manifold. Service 1. Foam wrap is washable (hot soapy water, then air dry). 2. Paper element can be cleaned by lightly tapping to remove debris. NOTE: Do not use compressed air to clean paper element. 3. Replace filter if damaged or contaminated by oil, gas, water, etc. NOTE: The replacement air filter includes both the paper and foam elements. Installation 1.
TWO BARREL CARBURETOR AND FUEL SYSTEM Fuel System.......................................................................................................................... 3-2 Introduction..................................................................................................................... 3-2 Operation......................................................................................................................... 3-2 Components.........................................................
TWO BARREL CARBURETOR AND FUEL SYSTEM This section covers the description, location, and operation of the fuel system including the two-barrel carburetor, cast aluminum intake manifold, fuel lines, fuel filter, and fuel pump. WARNING: Unauthorized adjustment to the carburetor or fuel system may make the machine noncompliant to EPA standards. Verify components are set to factory standards. WARNING Explosive fuel can cause fires and severe burns. Do not fill fuel tank while engine is hot or running.
TWO BARREL CARBURETOR AND FUEL SYSTEM Components Fuel Pump and Hoses: The fuel pump is a pulse diaphragm style pump, located on the #1 cylinder shroud. The pulse line connects to the intake manifold above the #1 cylinder head. The change in vacuum at the #1 cylinder intake pulses the diaphragm of the fuel pump. The vacuum supplied is a pulse, less than two psi, not a constant vacuum that is measurable. Two Barrel Carb.
TWO BARREL CARBURETOR AND FUEL SYSTEM Two Barrel Carburetor Exploded View K S T Q R C V W U AI B S X A AF Y X S Z Z AF AD AE AB AA AG AC D E F G H P I J M AH K N O L Figure 3 A. Carburetor Gasket B. Carburetor Body C. Carburetor Gasket D. Needle Float E. Float F. Float Pin G. Screw H. Gasket (Bowl) I. Gasket (Nozzle) 3-4 Table of Contents J. Carburetor Bowl K. Screw (Bowl Mount) L. Drain Bolt M. Solenoid Valve N. Spring O. Washer P. Solenoid Body Q. Pilot Jet R. Washer S.
TWO BARREL CARBURETOR AND FUEL SYSTEM Two-Barrel Carburetor Two Barrel Carb./Fuel Introduction: The two-barrel carburetor has the advantage of a unique fuel-air mix for each cylinder. Each barrel has a main jet, nozzle and pilot jet to maximize each cylinder’s output. The two-barrel carburetor is located between the intake manifold and the air filter manifold. All components are made of aluminum for durability (Figure 4).
TWO BARREL CARBURETOR AND FUEL SYSTEM Operation (Cont.) Fast Throttle: The fuel-air mix is metered by the main circuit. The throttle discs open, engine is under medium to full load, air is drawn through each barrel and the venturi creates a low pressure. Air at atmospheric pressure in the float bowl pushes on the fuel. Fuel is metered through the main jets and enters through the nozzles. The nozzle has a series of holes for air to mix with the fuel. Fuel-air mixture flows up the nozzle and into the venturi.
TWO BARREL CARBURETOR AND FUEL SYSTEM Operation (Cont.) Two Barrel Carb./Fuel NOTE: DO NOT remove the override choke components as they are press fit into the carburetor. If removed, a new carburetor is required (Figure 6). Figure 6 Solenoid: The fuel shut-off solenoid is located in the lower part of the carburetor float bowl. Its function is to shut off the fuel flow to the main jets of the carburetor when the engine is shut off.
TWO BARREL CARBURETOR AND FUEL SYSTEM Items to check prior to carburetor analysis NOTE: Items listed below are not in any particular order, one or more may apply.
TWO BARREL CARBURETOR AND FUEL SYSTEM Troubleshooting Engine starts hard, runs rough or stalls at idle speed Engine runs rich (indicated by black, sooty exhaust smoke, misfiring, loss of speed and power, governor hunting or excessive throttle opening) Possible Fuel system Causes Low speed, RPM setting too slow Air leak in pilot jet circuit Restricted air cleaner filter Choke partially closed during operation Air leak in pilot jet circuit Engine runs lean (indicated by misfiring, loss of speed and power,
TWO BARREL CARBURETOR AND FUEL SYSTEM Troubleshooting (Cont.) Problem Engine Cranks over but won’t start Possible Fuel System Causes Fuel solenoid closed -Inspect fuel solenoid for proper operation or debris, blocked valve Choke not closed -Check choke system for proper operation: cable adjustment, shaft/ butterfly not binding, choke spring length, and debris Blockage in jets, nozzles, or pilot circuit Fuel level too low in bowl 3-10 Table of Contents Next Step...
TWO BARREL CARBURETOR AND FUEL SYSTEM Disassembly Solenoid 1. Loosen and remove solenoid from the carburetor bowl. Two Barrel Carb./Fuel 2. Remove spring and solenoid valve if they remain in the carburetor bowl. NOTE: A small magnet may be used to assist removal. 3. Inspect spring and valve for damage (Figure 8).
TWO BARREL CARBURETOR AND FUEL SYSTEM Disassembly (Cont.) Float Bowl and Gaskets NOTE: The float bowl is a shared chamber for both main jet nozzles. The fuel solenoid and the bowl drain bolt mount to the float bowl. The main nozzles are sealed with an o-ring gasket (I) (Figure 9) that fits into the float bowl. The bowl gasket (H) is an o-ring gasket that fits into a groove of the float bowl (J). H I J Figure 9 1. Remove the four screws and float bowl.
TWO BARREL CARBURETOR AND FUEL SYSTEM Disassembly (Cont.) Float Bowl and Gaskets (Cont.) 3. Inspect the float bowl for corrosion, contamination or old fuel residue. Two Barrel Carb./Fuel 4. Replace if damaged or unable to clean. Float and Needle 1. Loosen the screw (G) (Figure 11), remove the float pin (F). Remove the float (E) and needle (D). D E F G Figure 11 2. Inspect the float for cracks, or if liquid is inside. Test the float to make sure it floats. 3.
TWO BARREL CARBURETOR AND FUEL SYSTEM Disassembly (Cont.) Float and Needle (Cont.) B C A Figure 13 A. Float B. Float Pin C. Needle 5. Inspect the seat for corrosion, old fuel residue, debris. NOTE: Use of a magnifying glass is recommended. 6. Replace components if damaged or unable to clean. NOTE: Pop Off testing in section 3, page 3-36.
TWO BARREL CARBURETOR AND FUEL SYSTEM Disassembly (Cont.) Main Jets and Nozzles NOTE: The main jets and nozzles are serviced as a kit (two nozzles, two jets). Two Barrel Carb./Fuel 1. Using a flat screwdriver, loosen and remove the main jets (AG) (Figure 14). NOTE: Main jets and nozzles are made of brass and easily damaged. AF AF AG Figure 14 2. Remove the main nozzles (AF) (Figure 14).
TWO BARREL CARBURETOR AND FUEL SYSTEM Disassembly (Cont.) Main Jets and Nozzles (Cont.) NOTE: To assist in removing a nozzle, a straightened paper clip with just the tip folded over can be inserted into the nozzle, hooking the top and gently pulling the nozzle out. 3. Inspect the jets and nozzles for debris clogging the small orifices. 4. Replace if unable to clean or damaged. NOTE: Clean with carburetor cleaner or ultrasonic cleaner. Do not use metallic tools to clean.
TWO BARREL CARBURETOR AND FUEL SYSTEM Disassembly (Cont.) Pilot Jets NOTE: Serviced as a kit containing both pilot jets and a retaining screw with washer. Two Barrel Carb./Fuel 1. Remove the screw (K) (Figure 16) and washer (R) at the top of the carburetor, near the fuel inlet. K Q R Figure 16 2. Remove each pilot jet (Q) (Figure 16) using a small flat screwdriver to carefully remove. NOTE: Do NOT twist when removing.
TWO BARREL CARBURETOR AND FUEL SYSTEM Disassembly (Cont.) Pilot Jets (Cont.) 3. Inspect the small orifice on the tip of each jet. 4. Inspect the o-rings for cuts or damage. NOTE: Clean with carburetor cleaner or ultrasonic cleaner. Do not use metallic tools to clean. 5. Replace if unable to clean or if damaged.
TWO BARREL CARBURETOR AND FUEL SYSTEM Disassembly (Cont.) Throttle Shaft Two Barrel Carb./Fuel 1. Remove the four screws and both throttle discs (Figure 18). Figure 18 2. Unhook the throttle shaft spring while sliding the shaft out of the carburetor body (Figure 19).
TWO BARREL CARBURETOR AND FUEL SYSTEM Disassembly (Cont.) Throttle Shaft (Cont.) 3. Inspect the shaft, spring, bushings and discs for wear or damage (Figure 20). Figure 20 4. Replace if damaged or worn (Figure 21).
TWO BARREL CARBURETOR AND FUEL SYSTEM Disassembly (Cont.) Choke Shaft 1. Remove the two screws (S) (Figure 22) and choke butterfly (V). Two Barrel Carb./Fuel 2. Remove the outer plastic cap (T) (Figure 22) from the override assembly. S T V W U Figure 22 NOTE: If needed, use a screwdriver to remove the outer plastic cap. 3. Slide the shaft with the spring out of the black override assembly. Remove from the carburetor body (Figure 23).
TWO BARREL CARBURETOR AND FUEL SYSTEM Disassembly (Cont.) Choke Shaft (Cont.) NOTE: Do not remove the vacuum override parts (retaining plate and screws, bushing, plastic arm and spring). Replace entire carburetor if removed (Figure 24). Figure 24 4. Inspect the choke shaft, spring and choke butterfly for wear or damage. 5. Replace components if damaged or worn.
TWO BARREL CARBURETOR AND FUEL SYSTEM NOTE: Always remove the following components prior to cleaning with a soak tank or ultrasonic cleaner: -Solenoid Assembly -Carburetor Bowl and Gaskets -Float and Needle -Main Jets and Nozzles -Pilot Jets -Throttle Shaft Assembly -Choke Shaft Assembly WARNING Use a carburetor soak container or ultrasound to thoroughly clean the carburetor body and float bowl, follow the carburetor cleaner manufacturer’s guidelines.
TWO BARREL CARBURETOR AND FUEL SYSTEM Assembly NOTE: Replace bowl gaskets and float needle. NOTE: If choke override was accidentally removed, replace carburetor assembly. Choke Shaft 1. Insert the spring with the inner end in the short slot of the override assembly, place the other end resting on the outer edge (Figure 25). Figure 25 2. Place a drop of motor oil on each bearing surface of the choke shaft. 3.
TWO BARREL CARBURETOR AND FUEL SYSTEM Assembly (Cont.) Choke Shaft (Cont.) Two Barrel Carb./Fuel 4. Apply slight pressure to keep the spring hooked, rotate the shaft counter-clockwise until it drops into the short slot of the override assembly (Figure 27). Figure 27 5. Snap on the outer cap to keep the shaft in position. 6. Insert the choke butterfly above the choke shaft in the fully open position (Figure 28).
TWO BARREL CARBURETOR AND FUEL SYSTEM Assembly (Cont.) Choke Shaft (Cont.) NOTE: Plate only fits one way, the deeper narrow slot goes toward the carburetor (Figure 29). Figure 29 7. Rotate the shaft and butterfly to the fully closed position, attach the choke butterfly with the two screws. 8. Verify the choke shaft rotates freely and the override functions: -Check that the choke assembly is free to rotate, choke fully opens by the spring action.
TWO BARREL CARBURETOR AND FUEL SYSTEM Assembly (Cont.) Throttle Shaft X Y Two Barrel Carb./Fuel 1. Place a drop of motor oil on each bearing surface of the shaft (Figure 30). X Figure 30 2. Install the spring and guides onto the throttle shaft if previously removed. Place a plastic guide (X) (Figure 30) on each side of the spring (Y). The long end of the spring is toward the carburetor, the short end hooks over the tang. 3.
TWO BARREL CARBURETOR AND FUEL SYSTEM Assembly (Cont.) Throttle Shaft (Cont.) 4. Connect the spring to the carburetor and the shaft tang: -Hook the long end into the hole of the carburetor body (Figure 31). -Hook the outer end to the tang that contacts the idle speed screw (Figure 32). The tang is clockwise from the throttle link connector. Figure 31 5. Rotate shaft counter-clockwise until the tang is past the idle screw, fully insert the shaft (Figure 32).
TWO BARREL CARBURETOR AND FUEL SYSTEM Assembly (Cont.) Throttle Shaft (Cont.) Two Barrel Carb./Fuel 6. Install the throttle discs with the top of the disc inserted first, retain with four screw (Figure 33). Figure 33 7. Verify the shaft is free to rotate and closes by the spring action (Figure 32).
TWO BARREL CARBURETOR AND FUEL SYSTEM Assembly (Cont.) Pilot Jets 1. Lightly lubricate the o-rings with engine oil. 2. Align the flat of the jet to match the carburetor casting. Slowly, insert into position, do not twist when installing (Figure 34). Figure 34 3. Repeat for other jet. 4. Retain with a screw and washer.
TWO BARREL CARBURETOR AND FUEL SYSTEM Assembly (Cont.) Main Nozzles and Jets Two Barrel Carb./Fuel 1. Install the main nozzle with the wider shoulder inserted first, double shoulder is last (Figure 35). Figure 35 2. Install the threaded jet and tighten with fingers, tighten using a flat screwdriver. NOTE: When fully installed, jet is slightly lower than flush. 3. Repeat for other nozzle and jet.
TWO BARREL CARBURETOR AND FUEL SYSTEM Assembly (Cont.) Needle and Float 1. Install the needle onto the tang of the float, needle tip pointed toward float (Figure 36). Figure 36 NOTE: The tang has a slight hook to retain the needle. 2. Slide the needle into the seat while aligning the pivot of the float. 3. Install the float pin and clamp by tightening the screw (Figure 37). Figure 37 NOTE: Verify the pin is fully inserted in the groove of the carburetor body. 4.
TWO BARREL CARBURETOR AND FUEL SYSTEM Assembly (Cont.) Float Bowl and Gaskets 1. Install a new o-ring gasket in the float bowl for the main nozzle (Figure 38). Two Barrel Carb./Fuel A B Figure 38 A. Float Bowl O-Ring Gasket B. Main Nozzle O-Ring Gasket 2. Install a new bowl o-ring gasket onto the float bowl. 3. Align the two pins of the float bowl to the two holes in the carburetor body (Figure 39). Figure 39 4. While holding the bowl to the carburetor body, use fingers to tighten the four screws.
TWO BARREL CARBURETOR AND FUEL SYSTEM Assembly (Cont.) Solenoid 1. Assemble solenoid (Figure 40): -Install spring into solenoid body, smaller coils of spring toward needle -Install needle into solenoid body, tip facing outward -Install new gasket Figure 40 2. Install the solenoid assembly into the float bowl. 3. Torque the solenoid to 89 in-lbs. (10 Nm).
TWO BARREL CARBURETOR AND FUEL SYSTEM Adjusting Idle Speed NOTE: Perform adjustments with engine at operating temperature. 2. Adjust the idle speed screw with the engine idling, to obtain the recommended engine idle speed of 1800 ± 150 RPM (Figure 41). Figure 41 NOTE: The carburetor does not have any additional adjustments. Twin Cylinder Engine Service Manual February 2017 - Digital Edition 3-35 Table of Contents Two Barrel Carb./Fuel 1. Verify idle speed RPM with tachometer.
TWO BARREL CARBURETOR AND FUEL SYSTEM Carburetor Testing Pop Off Test 1. With carburetor removed, position with float bowl up. 2. Using a hand pressure tester, apply pressure to the fuel inlet. NOTE: Follow tester instructions. 3. While pumping, observe the pressure increase. 4. Stop pumping, observe the pressure drop slightly, then stabilize as the float weight closes the needle and holds pressure. The pressure should not drop to zero.
CONTROL PLATE (THROTTLE AND CHOKE) Table of Contents Engine Controls Operation................................................................................................. 4-2 Introduction..................................................................................................................... 4-2 Cable Location..................................................................................................................... 4-3 Throttle and Choke Cable Mounts...............................
CONTROL PLATE (THROTTLE AND CHOKE) This section covers the description, location, and operation of the engine controls including throttle and choke cable mounting, governor troubleshooting, “zero” adjustment and top no-load RPM adjustment. WARNING: Unauthorized adjustment to the carburetor or fuel system may make the machine noncompliant to EPA standards. Make sure components are set to factory standards. WARNING Explosive fuel can cause fires and severe burns.
CONTROL PLATE (THROTTLE AND CHOKE) Cable Location Throttle and Choke Cable Mounts: The throttle cable is the upper cable, choke cable is the lower cable. The conduit is clamped below with an anchor screw (Figure 2). A Control Plate B Figure 2 A. Throttle Cable B.
CONTROL PLATE (THROTTLE AND CHOKE) Control Plate Exploded View L A B D C I E F G J H K Figure 3 A. Choke Linkage Clip B. Choke Linkage C. Choke Spring D. Governor Arm Bolt E. Flange Nut F. Governor Arm 4-4 Table of Contents G. Governor Spring H. Control Plate Assembly I. Throttle Linkage J. Throttle Cable Clamp K. Choke Cable Clamp L.
CONTROL PLATE (THROTTLE AND CHOKE) Adjustments Control Plate Choke Cable (Figure 4) Figure 4 1. Move the control lever to full choke and hold. 2. Loosen the clamp. 3. Pull the conduit to the right to remove the slack in the cable. 4. Tighten the clamp on the control plate. 5. Verify proper operation of choke. NOTE: During start-up, the cable may not stay in the full choke position unless the operator holds it. NOTE: Choke must be fully closed for maximum fuel pump output.
CONTROL PLATE (THROTTLE AND CHOKE) Adjustments Throttle Cable (Figure 5) Figure 5 1. Move control lever to “fast speed” setting (full forward) and hold. NOTE: There is a slight detent. 2. Loosen the clamp. 3. Pull the conduit to the right to remove slack in the cable. 4. Tighten the clamp on the control plate. 5. Verify all linkages are free to move. 6. Check top no-load RPM; see “Top No-Load RPM,” chapter 4, page 4-9.
CONTROL PLATE (THROTTLE AND CHOKE) Linkages and Springs Introduction: The control plate and the governor control the carburetor with linkages and springs. Control Plate Operation Choke Linkage: Connects the choke override lever to the choke pivot on the control plate. It is located on the number one cylinder side of the carburetor. The upper end of the link has a quick clip for easy carburetor removal. The choke linkage is longer than the throttle linkage, and has multiple bends (Figure 6).
CONTROL PLATE (THROTTLE AND CHOKE) Linkages and Springs (Cont.) Throttle Linkage: Located on the number two cylinder side of the carburetor. Connects governor arm to the throttle shaft. The upper end connects to the throttle shaft with a quick clip for easy carburetor removal. The lower end connects to the governor arm. The throttle linkage is shorter than choke linkage, and has fewer bends (Figure 8).
CONTROL PLATE (THROTTLE AND CHOKE) Linkages and Springs (Cont.) Disassembly Link (Choke or Throttle) 1. Unclip the quick clip (A) (Figure 3) and rotate away from link. 2. Remove the upper end from the carburetor. 3. Unhook the lower end and remove the link (Figure 10). Throttle Clip Control Plate Choke Clip Figure 10 Adjustment Top No-Load RPM A) Verify 1. Start and run engine until at operating temperature. 2. Move the throttle control to “Fast Speed” setting. 3.
CONTROL PLATE (THROTTLE AND CHOKE) Adjustment (Cont.) Top No-Load RPM (Cont.) B) Adjust 1. Insert pin into alignment hole through the control plate and throttle pivot arm (Figure 11). Figure 11 NOTE: Examples of a pin: hex key, end of drill bit, solid rod, screwdriver, etc. 2. Change speed by bending the governor spring anchor on the control plate. -Increase speed (elongate spring): insert pliers and rotate clockwise (CW) to bend anchor.
CONTROL PLATE (THROTTLE AND CHOKE) Adjustment (Cont.) Governor “Zero” 1. Engine off. 2. Verify throttle is in (Wide Open Throttle) WOT position. NOTE: Governor spring pulls to WOT when throttle control is set to “fast speed.” 3. Slightly loosen clamp nut/bolt on governor arm. 4. Rotate D of governor shaft counter-clockwise (CCW) while maintaining WOT. 5. Hold and tighten clamp nut/bolt. NOTE: Internal engine damage will occur if engine is operated with clamp loose. Control Plate 6.
CONTROL PLATE (THROTTLE AND CHOKE) Troubleshooting Engine Surging/Hunting 1. Start and run engine until at operating temperature. 2. Move throttle control to “fast speed” setting. 3. Check RPM with tachometer, top no-load RPM 3300 ± 100 RPM. NOTE: See “Top No-Load RPM,” chapter 4, page 4-9. 4. If RPM varies beyond limits: -Verify adequate clean air. -Verify adequate clean fresh fuel supply. -Verify not caused by parasitic load (transmission or clutch). 5.
ELECTRICAL SYSTEM AND COMPONENTS Table of Contents Electrical System Components Exploded View................................................................ 5-2 Spark Circuit......................................................................................................................... 5-3 Spark Plugs..................................................................................................................... 5-3 Ignition Coils................................................................
ELECTRICAL SYSTEM AND COMPONENTS Electrical System Components B A D D F E E C F Figure 1 A. Electric Starter B. Flywheel C. Stator (Alternator) 5-2 Table of Contents D. Ignition Coils E. Spark Plugs F.
Schematics ELECTRICAL SYSTEM AND COMPONENTS This section covers the description, location, and operation of the electrical system components including the charging system, electric starter, and the ignition spark circuit. WARNING Electric shock can cause injury. Do not touch wires while engine is running. Spark Circuit Electrical The spark circuit components include the two ignition coils, flywheel magnets, and spark plugs.
ELECTRICAL SYSTEM AND COMPONENTS Charging System Introduction: The charging system components include the stator, voltage regulator with the wiring harness, and flywheel (Figure 1). Flywheel: Located under the blower shroud and mounted to the upper end of the crankshaft, made of cast iron and permanent magnets (two exterior and twenty interior). Magnets create magnetic field for ignition coils to create spark, and stator to create AC voltage.
ELECTRICAL SYSTEM AND COMPONENTS Charging System Testing NOTE: Use the three stator tests below to determine if the flywheel or stator has failed. OHM Resistance Test Across the Leads 1. Shut engine off. 2. Set Digital Multi-Meter to OHMs. 3. Connect Digital Multi-Meter leads to stator leads. Electrical NOTE: Unplug from engine harness. Figure 4 4. Measure the resistance. Expected measurement should be less than one OHM (component at room temperature). 5.
ELECTRICAL SYSTEM AND COMPONENTS Charging System Testing (Cont.) OHM Resistance Test to Ground 1. Shut off the engine. 2. Set Digital Multi-Meter to OHMs. 3. Connect one Digital Multi-Meter lead to either stator lead. NOTE: Unplug from engine harness. 4. Connect other Digital Multi-Meter lead to ground (stator frame or engine block if stator mounted to the engine block). 5. Measure the resistance. Expected measurement should be (high resistance) infinity (component at room temperature). 6.
ELECTRICAL SYSTEM AND COMPONENTS Charging System Testing (Cont.) AC Volts Output at Leads 1. Engine running at Top No-Load RPM (3300 RPM). 2. Set Digital Multi-Meter to AC volts. 3. Connect both Digital Multi-Meter leads to each stator lead. 4. Measured AC volts. Expected reading should be minimum of 30 VAC at top no-load RPM. 5. If measure voltage is below 30 volts AC, inspect flywheel for broken or cracked magnets. 6. Replace flywheel if magnets are damaged. 7. Repeat step 4. Electrical 8.
ELECTRICAL SYSTEM AND COMPONENTS Ignition Coil Testing Ignition Coil Test: NOTE: Either bench test or test mounted to the engine. 1. Set Digital Multi-Meter to OHMs. 2. Primary coil test (Figure 5) -Connect one lead to the ground terminal of the coil (harness wire removed). -Connect other lead to the iron core of the coil. -Measure resistance, primary coil resistance 1.6-1.9 Ω Figure 5 3. Replace ignition coil if measured resistance is out of range.
ELECTRICAL SYSTEM AND COMPONENTS Ignition Coil Testing (Cont.) Ignition Coil Test (Cont.): 4. Secondary coil test (Figure 6) -Connect one lead to the spark plug’s high tension terminal. -Connect the other lead to the iron core of the coil. -Measure resistance, secondary coil resistance 6.2-7.1 KΩ. Electrical Figure 6 5. Replace ignition coil if out of specification.
ELECTRICAL SYSTEM AND COMPONENTS Ignition Coil Testing (Cont.) Testing spark while engine is operating 1. Shut off the engine. 2. Connect in-line spark tester between the spark plug’s high tension terminal and the spark plug (Figure 7). Figure 7 3. If two testers are available both coils can be checked at once. 4. Start the engine. 5. Monitor tester(s) for spark at both idle and fast throttle. NOTE: Spark plug condition affects testing accuracy.
ELECTRICAL SYSTEM AND COMPONENTS Ignition Coil Testing (Cont.) Testing spark using electric starter only WARNING Avoid fire and explosion. This test creates open spark which could ignite spilled fuel. 1. Connect spark tester to spark plug’s high tension terminal. NOTE: Do not remove the spark plugs. 2. Ground tester to engine block. NOTE: Tester must have good ground to cylinder block, not plastic. 3. If two testers are available, both coils can be checked at once.
ELECTRICAL SYSTEM AND COMPONENTS Voltage Regulator Testing Setup 1. Shut off the engine. 2. Verify the battery is in good condition (minimum 12.5 VDC). NOTE: If weak or no battery in the circuit, voltage regulator output will be zero. 3. Measure the battery voltage at the battery for baseline voltage reading. Test 1 (Complete Circuit Test) 1. Set Digital Multi-Meter to DC volts. - Connect the red lead to the positive post of the battery. - Connect the black lead to the negative post of the battery. 2.
ELECTRICAL SYSTEM AND COMPONENTS Voltage Regulator Testing (Cont.) Test 2 (Circuit Test without Chassis Harness) 1. Set Digital Multi-Meter to DC volts. - Connect the red lead to the red wire of the engine harness plug (DO NOT unplug from chassis harness). - Connect the black lead to the negative post of the battery. 2. Start the engine. 3. Measure the battery voltage as engine speed increases from idle to fast. 4. Compare to expected voltage (battery voltage up to 15.
ELECTRICAL SYSTEM AND COMPONENTS Voltage Regulator Testing (Cont.) Test 3 (Test Voltage Regulator Only) 1. Set Digital Multi-Meter to DC volts. - Connect the red lead to the red wire of the engine harness plug (DO NOT unplug from chassis harness). - Connect the black lead to the ground on the engine block. 2. Start the engine. 3. Measure the battery voltage as engine speed increases from idle to fast. 4. Compare to expected voltage. Expected voltage range (battery voltage up to 15.
ELECTRICAL SYSTEM AND COMPONENTS Electric Starter Testing Bench Test WARNING Avoid lacerations and amputations. This test has exposed rotating parts. 1. Clamp the mounting ear of the starter in the vice. NOTE: Do not clamp circular motor body. 2. Apply battery voltage to electric starter terminal. 3. Apply ground momentarily (2 seconds) to base of starter. 3. Observe starter and Bendix gear action. 4. Replace starter if failed test. Electrical Test on Engine 1. Turn the ignition key off. 2.
LUBRICATION SYSTEM Table of Contents Lubrication Components Exploded View............................................................................ 6-2 Oil Flow.................................................................................................................................. 6-3 Oil Filtration..................................................................................................................... 6-3 Oil Pressure Circuit...........................................................
LUBRICATION SYSTEM Lubrication Components A B G C J D E I H F K L M R Q P O N S Figure 1 A. Oil Filter B. Adapter Fitting C. O-Rings D. Crankshaft E. Crankshaft Gear F. Sump Cover Gasket G. Crankcase 6-2 Table of Contents H. Cover (Check Ball Assembly) I. Spring (Check Ball Assembly) J. Check Ball K. Cover (Screen Assembly) L. Retainer (Screen Assembly) M. Screen N. Sump Cover O. Oil Pump Shaft P. Gerotor (Inner) Q. Gerotor (Outer) R. O-Ring S.
LUBRICATION SYSTEM This section covers the components for the lubrication system. The system uses a gerotor pump to provide pressurized oil to the following critical bearing surfaces; upper and lower crankshaft, connecting rod journals. Oil Flow Oil Filtration: Mesh screen in crankcase sump cover, spin-on oil filter. Oil Pressure Circuit: Gerotor Pump (gear pump) located at the lowest point of the crankcase sump. Driven by the camshaft, draws oil through the screen and creates pressurized oil.
LUBRICATION SYSTEM Maintenance (Cont.) 3. Lower the hose into the drain pan. 4. Drain the oil. 5. Place a drain pan under the oil filter and remove. 6. Remove and discard oil filter gasket if still on the cylinder block. 7. Once oil has drained, install hose into the cleat and slide onto shroud fitting. 8. Install the new oil filter. NOTE: Verify oil filter gasket from step 6 is removed. 9. Tighten filter until the gasket contacts the engine block, continue tightening 3/4 turn or torque 106 in-lbs. (12 Nm).
ENGINE DISASSEMBLY Table of Contents Upper Disassembly 1 Exploded View............................................................................... 7-2 Upper Disassembly 2 Exploded View............................................................................... 7-3 Lower Disassembly 1 Exploded View............................................................................... 7-4 Lower Disassembly 2 Exploded View...............................................................................
ENGINE DISASSEMBLY Upper Disassembly 1 A T O Q P J R N M B S C D EJ L L F G H I Figure 1 A. Blower Shroud B. Shredder Screen C. Flywheel Fan D. Bolt E. Washer F. Flywheel G. Stator H. Lower Baffle I. Electric Starter J. Side Shroud K. Oil Drain Hose Cleat L. Ignition Coil M. Fuel Line N. Fuel Pump O. Fuel Filter P. Fuel Line Q. Vacuum Line R. Side Shroud S. Paper Element T. Foam Element NOTE: Mounting components not shown.
ENGINE DISASSEMBLY Upper Disassembly 2 R D E F Q A C B P G I J M N L O K Disassembly H Figure 2 A. Flywheel Key B. Upper Seal C. Breather Assembly D. Intake Manifold E. Carburetor F. Throttle Link G. Choke Link H. Fuel Tank Vent Line I. Air Filter Manifold J. Choke Spring K. Control Plate L. Throttle Spring M. Head Gasket N. Cylinder Head O. Valve Cover P. Alignment Pin Q. Voltage Regulator and Wire Harness R. Dipstick and Tube NOTE: Mounting components not shown.
ENGINE DISASSEMBLY Lower Disassembly 1 B H G A F D E E C Figure 3 A. Governor Rod B. Crankcase C. Camshaft D. Crankshaft E. Connecting Rod F. Piston (1 shown) G. Oil Filter H. Oil Filter Threaded Fitting NOTE: Mounting components not shown.
ENGINE DISASSEMBLY Lower Disassembly 2 A W V U B D C T S X G R E F H I J Q K P L M N Disassembly O Figure 4 A. Oil Screen Cover B. Oil Screen C. Screen Retainer D. Rubber Oil Deflector E. Spool (Gov. Asm.) F. Retaining Ring (Gov. Asm.) G. Gear w/Fly Weights (Gov. Asm.) H. Anchored Washer (Gov. Asm.) I. Shaft (Gov. Asm.) J. Seal K. Oil Pump Shaft (Oil Pump Asm.) L. Inner Rotor (Oil Pump Asm.) M. Outer Rotor (Oil Pump Asm.) N. O-Ring O. Oil Pump Cover P. Hose Fitting Q. Oil Drain Hose Asm.
ENGINE DISASSEMBLY This chapter covers the complete disassembly of the Toro Twin Cylinder engine, 2P77F. It includes suggested sequence steps for complete engine disassembly. NOTE: Details of the unique features such as the air filter system, two-barrel carburetor, engine controls, and pressurized lubrication system are in other chapters. Clean all parts before making measurements. If using chemicals or solvents to clean, be sure they are thoroughly removed from the parts before reassembling the engine.
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Engine Shroud a. Blower Shroud Removal NOTE: The blower shroud is retained with six identical shoulder bolts (Figure 6). Figure 6 1. Loosen each bolt a few turns. 2. Remove the blower shroud with the fan cover and air filter door attached. Disassembly NOTE: Remove the oil drain hose from the shroud if it was reattached after draining the oil.
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Engine Shroud (Cont.) b. Cylinder Side Shrouds NOTE: Both cylinders have a plastic shroud to provide proper cooling. Each shroud is mounted with two upper bolts and one lower bolt. #1 Cylinder Shroud NOTE: The #1 cylinder shroud has the fuel pump mounted to it. Figure 7 1. Remove the fuel pump vacuum line from the intake manifold near the #1 cylinder (Figure 7). 2. Remove the fuel supply line from the top of the carburetor. 3.
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Engine Shroud (Cont.) b. Cylinder Side Shrouds (Cont.) #2 Cylinder Shroud NOTE: The #2 cylinder shroud has the oil drain hose cleat mounted to it (Figure 8). Figure 8 1. Remove the oil drain hose from the cleat. 2. Remove the three mounting bolts two upper and one lower. Disassembly 3. Remove the shroud with the cleat still attached.
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Ignition Coils 1. Remove the two mounting bolts for each coil. 2. Lift each coil and remove it’s ground wire terminal. NOTE: Remove the spark plug boots from the spark plugs if not previously removed. 3. Remove the ignition coils (Figure 9).
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Electric Starter 1. Remove the two mounting bolts and the electric starter (Figure 10). NOTE: One bolt retains the engine lift bracket.
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Flywheel/Screen/Fan 1. Remove the blower shroud (Figure 11) (if not previously removed), see “Engine Shroud,” chapter 7, page 7-7. Figure 11 2. Remove the four screws retaining the shredder screen and remove the shredder screen. 3. Remove the four bolts retaining the cooling fan and remove the cooling fan. 4. Remove the flywheel bolt and washer. NOTE: Remove ignition coils if not previously removed, see “Ignition Coils,” chapter 7, page 7-10.
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Flywheel/Screen/Fan (Cont.) 5. Remove the flywheel, use a two or four bolt puller. NOTE: Lift the flywheel straight upward so that the charging magnets on the underside. Do not contact the stator. 6. Remove the flywheel key with a side cutter or pliers (Figure 12).
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Lower Baffle 1. Remove the shoulder bolt retaining the dipstick tube to the baffle. 2. Remove the four bolts mounting the baffle to the engine block and remove the baffle (Figure 13). Figure 13 Stator (Alternator) 1. Unplug the two stator wires from the wire harness near the dipstick tube. 2. Remove the four mounting bolts to the engine block. 3. Remove the stator assembly (Figure 14).
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Breather Assembly NOTE: The breather is located on the top of the engine block between the flywheel and the intake manifold, between the two cylinders. Remove the flywheel to access the breather (Figure 15). A Figure 15 A. Breather 1. Remove the four bolts and cover. Disassembly 2. Remove the gasket and discard.
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Breather Assembly (Cont.) 3. Remove the breather filter (blue sponge). 4. Remove the bolt retaining the breather reed assembly (Figure 17). Figure 17 5. Remove the breather reed.
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Air Filter Manifold NOTE: The air filter manifold is made of cast aluminum for durability. Both the engine breather and the fuel tank vent ports attach to it, see “Air Filter Manifold,” chapter 2, page 2-4. 1. Remove the four nuts retaining the air filter manifold to the carburetor. 2. Cut the zip tie retaining the fuel tank vent hose to the intake manifold (Figure 18). Figure 18 3.
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Carburetor NOTE: The air filter manifold (previously removed), clamps the two-barrel carburetor to the intake manifold. Remove the blower shroud, if not previously removed, to access the carburetor, see “Engine Shroud,” chapter 7, page 7-7. 1. Remove the choke (Figure 19) and throttle (Figure 20) linkages by rotating the plastic clips at both the throttle shaft and choke override lever.
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Carburetor (Cont.) 3. Disconnect the fuel solenoid wire at the wire harness plug located near the #1 cylinder port of the intake manifold. Carefully remove the plug from between the intake manifold and the cylinder block (Figure 21). Figure 21 4. Slide the carburetor with the fuel solenoid off the mounting studs. 5. Remove any remaining gaskets and the insulator. Retain the insulator, discard the gaskets.
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Control Plate (Throttle/Choke) NOTE: The choke and throttle linkages were previously removed. 1. Remove the two mounting bolts, one from each cylinder head. 2. Unhook the governor spring from the governor arm. NOTE: Note the location of the spring on the governor arm, hole “C” (Figure 22). Figure 22 3. Remove the control plate.
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Intake Manifold NOTE: The intake manifold has the engine wire harness attached to it with zip ties. If reusing all components, remove as an assembly; intake manifold, wire harness and voltage regulator mounted to the dipstick tube (Figure 23). Figure 23 1. Remove two mounting bolts from the top of each head. 2. Remove the wire harness ground bolt located below the voltage regulator. Disassembly 3.
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Voltage Regulator with Wire Harness Refer to intake manifold removal, see “Intake Manifold,” chapter 7, page 7-21. NOTE: The voltage regulator contains the engine wire harness and is mounted to the dipstick tube (Figure 25). Figure 25 Dipstick and Tube 1. Remove the blower shroud shoulder bolt, if not previously removed. 2. Remove voltage regulator, if not previously removed, refer to “Voltage Regulator with Wire harness” above. 3.
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Cylinder Heads NOTE: The cylinder heads are unique; #1 cylinder is to the left of the carburetor and #2 cylinder is to the right of the carburetor. 1. Remove the four bolts and valve cover for each head, discard gaskets. Toro Twin Engine Head 2. Remove the five head bolts. NOTE: There are three longer bolts and two shorter bolts for each head (Figure 26 and 27).
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Cylinder Heads (Cont.) 3. Remove the cylinder head. 4.Remove the two alignment pins (Figure 28). Figure 28 NOTE: Each head has two alignment pins, retain for assembly. Discard head gaskets. 5. Remove each push rod and mark it for cylinder #1 or #2 and if exhaust or intake. Repeat for other side.
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Rockers and Valves (Cylinder Head Disassembly) NOTE: Keep each valve’s components separate and mark by cylinder #1 and #2 and whether exhaust or intake. TECH TIP: Use two empty egg cartons to keep the parts sorted, one for each head. Mark the cartons #1 and #2. Then mark each end of the cartons intake and exhaust. Place the corresponding parts into the correct carton (Figure 29 and 30).
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Rockers and Valves (Cylinder Head Disassembly) (Cont.) 1. While holding the rocker arm pivot (B) (Figure 31), loosen and remove the rocker lock nut (A). Repeat for other rocker. F E D A B C Figure 31 A. Rocker Lock Nut B. Rocker Arm Pivot C. Rocker Arm D. Rocker Arm Stud E. Push Rod Plate F. Cylinder Head 2. Remove the rocker arm pivot and rocker arm (B and C) (Figure 31). Repeat for other rocker. 3.
ENGINE DISASSEMBLY Disassembly Upper End (Cont.) Rockers and Valves (Cylinder Head Disassembly) (Cont.) 4. Use a valve spring compressor to compress the valve spring and remove the two valve keepers. Repeat for other valve. 5. Remove the remaining valve system components from the head (E) (Figure 32): -Spring retainers (A) -Valve springs (B) -Valve seals (C) -Valve spring seat (D) -Intake and exhaust valves (F) E C A F D B Figure 32 Disassembly NOTE: Repeat for other cylinder head.
ENGINE DISASSEMBLY Disassembly Lower End Oil Pump 1. Remove the three bolts and cover from the sump cover (Figure 33). Figure 33 2. Remove o-ring and discard (Figure 34). E A B D C Figure 34 A. O-Ring B. Inner Rotor C. Oil Pump Shaft D. Outer Rotor E. Oil Pump Cover 3. Remove the gerotor pump (B and D) (Figure 34). 4. Remove oil pump shaft (C) (Figure 34). NOTE: A magnet will assist in removing the gerotor pump from the sump cover.
ENGINE DISASSEMBLY Disassembly Lower End (Cont.) Sump Cover 1. Remove the oil pump assembly (A), if not previously removed, see “Oil Pump,” chapter 7, page 7-28. 2. Remove the ten (Figure 35) bolts retaining the sump cover to the engine crankcase. A Figure 35 3. Clean the crankshaft of rust and debris. 4. Remove the sump cover with the drain hose. NOTE: A plastic mallet will assist in loosening the cover from the crankcase. 5. Remove the two alignment pins.
ENGINE DISASSEMBLY Disassembly Lower End (Cont.) Sump Cover (Cont.) (Figure 36 and 37) A D B C Figure 36 A B C Figure 37 a. Pressure lube check ball system (A) (Figure 37) 1. Remove the screw and retainer. 2. Remove the spring and check ball. b. Oil pre-screen assembly (B) (Figure 37) 1. Remove the two screws and cover. 2. Remove the screen and retainer (Figure 37). c. Governor assembly (optional removal) (C) (Figure 37) 1. From the outside of the sump cover use a 7/32 in. or 15/64 in.
ENGINE DISASSEMBLY Disassembly Lower End (Cont.) Camshaft and Followers 1. Rotate the crankshaft until timing marks align. 2. Lift out camshaft. 3. Remove the four followers, marking each for cylinder #1 and #2 and whether intake and exhaust (Figure 38).
ENGINE DISASSEMBLY Disassembly Lower End (Cont.) Piston and Connecting Rod Assembly 1. Remove the connecting rod cap bolts and cap for each rod (Figure 39). Figure 39 NOTE: Each cap is stamped to match the connecting rod (Figure 40). The connecting rod body and the connecting rod cap have the same order number. Figure 40 2. Slide the piston and rod assembly out of the cylinder, away from crankshaft. 3. Repeat for other piston assembly. 4. Re-install matching rod cap and bolts to corresponding rod. 5.
ENGINE DISASSEMBLY Disassembly Lower End (Cont.) Piston Rings and Wrist Pin a. Piston rings 1. Remove each ring off the dome end of the piston; start with the top ring, middle and then the three piece oil ring (if reusing rings, be careful not to break them). NOTE: Use of a ring removal tool is optional. WARNING Use protective eye wear when removing the wrist pin. b. Wrist pin 1. Remove both piston pin clips. 2. Remove the piston pin.
ENGINE DISASSEMBLY Disassembly Lower End (Cont.) Crankshaft 1. Slide the crankshaft out of the crankcase (Figure 42).
ENGINE INSPECTION AND RECONDITIONING Table of Contents Upper End Inspection and Reconditioning...................................................................... 8-3 Cylinder Head Cleaning Inspection............................................................................. 8-3 Cylinder Head Valve Seat Inspection........................................................................... 8-4 Valve Face Contact Test..........................................................................................
ENGINE INSPECTION AND RECONDITIONING This chapter covers the inspection and reconditioning of primary engine components as listed in the table of contents. See engine exploded views in “Engine Disassembly” section, Figure 1, Figure 2, Figure 3 and Figure 4.
ENGINE INSPECTION AND RECONDITIONING Upper End Inspection and Reconditioning Cylinder Head Cleaning Inspection 1. Remove the carbon deposits. 2. Clean the cylinder head of any remaining gasket material; intake, exhaust, valve cover and head gaskets. 3. Inspect the cylinder head for cracks, specifically around the following (Figure 1): -Spark plug threads (A) -Valve seats (B) -Exhaust Port (C) -Intake Ports (D) -Coolant Fins (E) A C D B E Figure 1 4.
ENGINE INSPECTION AND RECONDITIONING Upper End Inspection and Reconditioning (Cont.) Cylinder Head Valve Seat Inspection Throughly clean the cylinder head to remove carbon deposits. 1. Inspect valve seats (Figure 2): -Loose Seat -Proper valve face contact (see steps below) -Proper seat width, standard 0.028-0.030 in., service limit 0.040 in. CONTACT too TOOhigh HIGH Contact Contact too low CONTACT TOO LOW Figure 2 2. Repeat inspection for all valves and seats.
ENGINE INSPECTION AND RECONDITIONING Upper End Inspection and Reconditioning (Cont.) Valve Face Contact Test 1. Apply a light coat of Prussian Blue or erasable felt-tipped marker ink to the valve face. 2. Insert the valve, lift valve and snap closed against the seat several times. NOTE: Be sure the valve does not rotate on the seat. 3. Inspect the transferred marking compound for any area of the seat that is not concentric. 4. Replace cylinder head if any of the above items are found out of specification.
ENGINE INSPECTION AND RECONDITIONING Upper End Inspection and Reconditioning (Cont.) Valve Inspection 1. Clean carbon from the valve (Figure 3). Figure 3 2. Inspect the valve stem for pitting, wear or if bent. Compare to standard. Stem Diameter Intake Standard Service Limit 0.258-0.259 in. 0.255 in. Exhaust 0.257-0.258 in. Replace the valve if the stem outside diameter is smaller than the service limit. 0.255 in. 3. Inspect valve face for pitting, wear or corrosion. 4.
ENGINE INSPECTION AND RECONDITIONING Upper End Inspection and Reconditioning (Cont.) Valve Seat Reconditioning 1. Using a 45-46° cutter, remove enough material to produce a smooth, concentric seat. Follow the valve seat cutter manufacturer’s instructions (Figure 4). Figure 4 NOTE: Turn the cutter clockwise, never counterclockwise, continue to turn the cutter while lifting from the valve seat. 2.
ENGINE INSPECTION AND RECONDITIONING Upper End Inspection and Reconditioning (Cont.) Valve Seat Reconditioning (Cont.) 3. Make a final light pass with a 45-46° cutter to remove any possible burrs at the edges of the seat. 4. After resurfacing the seats, inspect for even valve seating. 5. Refer to “Valve Face Contact Test,” chapter 8, page 8-5. NOTE: Replace the valve if not making full contact. 6. Repeat valve seat cutting for all seats. Valve Reconditioning (Lapping) 1.
ENGINE INSPECTION AND RECONDITIONING Upper End Inspection and Reconditioning (Cont.) Valve Reconditioning (Lapping) (Cont.) 7. Clean entire cylinder head and all valves of grinding compound with hot soapy water. 8. After drying, apply a light coat of engine oil. NOTE: To avoid severe engine damage, be sure to remove all lapping compound from the head and valve components before reassembling. Valve Spring 1. Inspect the free length of the valve spring. (Figure 6). Valve Spring Standard 1.55-1.60 in.
ENGINE INSPECTION AND RECONDITIONING Upper End Inspection and Reconditioning (Cont.) Push Rods 1. Inspect push rods for straightness and wear on the ball ends 2. Replace if bent or worn. Breather Assembly 1. Clean the breather filter (blue sponge) or replace if deteriorated. 2. Clean and inspect the reed assembly for burrs or cracks. Replace if damaged (Figure 7).
ENGINE INSPECTION AND RECONDITIONING Lower End Inspection and Reconditioning Crankshaft 1. Inspect all three bearings for wear, pitting or other damage. 2. Measure each bearing surface (upper bearing, rod bearing, and lower bearing), compare to specifications. (Figure 8). Crank Bearing Standard 1.5735-1.5744 in. (39.966-39.991 mm) Service Limit 1.5551 in. (39.50 mm) Figure 8 3. Inspect and clean lubrication channel from lower bearing to crank pin journal. 4. Inspect the timing gear teeth. 5.
ENGINE INSPECTION AND RECONDITIONING Lower End Inspection and Reconditioning (Cont.) Camshaft and Followers 1. Inspect timing gear teeth. 2. Inspect the Automatic Compression Relief (ACR) for free movement. NOTE: Only serial number 50,000 and lower have the ACR (Figure 9 and 10).
ENGINE INSPECTION AND RECONDITIONING Lower End Inspection and Reconditioning (Cont.) Camshaft and Followers (Cont.) 3. Measure the lobe heights, compare to specifications. Height (intake and exhaust) (Figure 11). Lobe Heights Standard 1.1791-1.1831 in. (29.95-30.05 mm) Service Limit 1.1713 in. (29.75 mm) Figure 11 4. Measure journals, compare to specifications. (Figure 12). Journal (Bearing) Standard (Height) 0.6286-0.6293 in. (15.966-15.984 mm) Service Limit Inspection 0.6266 (16.
ENGINE INSPECTION AND RECONDITIONING Lower End Inspection and Reconditioning (Cont.) Camshaft and Followers (Cont.) NOTE: Replace camshaft if out of specification. 5. Inspect camshaft followers for wear or damage on shaft or face. NOTE: Replace if worn or damaged. Crankcase 1. Inspect the cylinder bores (Figure 13). - Inspect for surface wear, pitting and scratches. - Inspect for cylinder taper and cylinder out of round. - Measure cylinder bore, compare to specifications.
ENGINE INSPECTION AND RECONDITIONING Lower End Inspection and Reconditioning (Cont.) Crankcase (Cont.) 2. Recondition the cylinder bore: - Hone cylinder bore to obtain crosshatch - Clean bore after honing with hot soapy water - Remeasure bore to specification in previous step (1c above). 3. Clean and remove all gasket material. Inspect all gasket surfaces for nicks and deep scratches. 4. Inspect the upper crankshaft bearing. - Remove and discard the upper crankshaft oil seal.
ENGINE INSPECTION AND RECONDITIONING Lower End Inspection and Reconditioning (Cont.) Pistons 1. Clean the pistons; remove carbon, debris from the piston dome and ring lands. 2. Inspect pistons for damage (scuffs, scoring or overheating). 3. Skirt outside diameter measurement: Measure and compare to specifications (Figure 15). Skirt Outside Diameter Standard (Height) 3.620-3.621 in. (76.965-76.975 mm) Service Limit 3.0219 in. (76.
ENGINE INSPECTION AND RECONDITIONING Lower End Inspection and Reconditioning (Cont.) Pistons (Cont.) 4. Ring land side clearance measurement: Measure and compare to specifications, (Figure 16). Ring to Groove (top and middle) Standard (Height) 0.00079-0.00236 in. (0.02-0.06 mm) Service Limit 0.00433 in. (0.11 mm) Figure 16 5. Piston to cylinder wall measurement: Measure and compare to specifications. Cylinder Clearance Standard (Height) 0.00098-0.00177 in. (0.025-0.045 mm) 0.01 in. (0.
ENGINE INSPECTION AND RECONDITIONING Lower End Inspection and Reconditioning (Cont.) Pistons (Cont.) NOTE: If piston is damaged or out of specification, replace piston, piston rings and piston clips. 6. Piston Pin (wrist) inspect and measure: Inspect pin and clips, measure and compare to specifications, (Figure 17). Piston Pin (Wrist) outside diameter Standard (Height) 0.669-0.6692 in. (16.992-16.998 mm) Service Limit 0.6654 (16.90 mm) Assembly: Sign .
ENGINE INSPECTION AND RECONDITIONING Lower End Inspection and Reconditioning (Cont.) Pistons (Cont.) 8. Piston Rings inspect and measure: Inspect each for surface wear, broken, pitting or scratches. Measure and compare each ring to specifications (Figure 19). Ring Thickness Ring Standard Service Limit Width (Top) 0.038-0.039 in. (0.97-0.99 mm) 0.0354 in. (0.90 mm) Width (Middle) 0.046-0.047 in. (1.17-1.19 mm) 0.0433 in. (1.10 mm) 0.110-126 in. (1.65-1.85 mm) 0.1063 in. (1.
ENGINE INSPECTION AND RECONDITIONING Lower End Inspection and Reconditioning (Cont.) Connecting Rods 1. Inspect the connecting rods for damage: -Bent: the rods are identical, compare side-by-side -Overheated: a good rod should be bright aluminum in color -Scored: inspect both rod ends for scuffs, pitting or scoring. Light faint scratches at crank journal is normal. 2. Wrist pin end inside diameter, measure and compare specifications (Figure 20). Connecting Rod Small End ID Standard 0.6695-0.6699 in.
ENGINE INSPECTION AND RECONDITIONING Lower End Inspection and Reconditioning (Cont.) Connecting Rods (Cont.) 3. Crankshaft end inside diameter, measure and compare to specifications (Figure 21). Connecting Rod Large End ID Standard 1.5754-1.5757 in. Service Limit 1.5773 in.
ENGINE INSPECTION AND RECONDITIONING Lower End Inspection and Reconditioning (Cont.) Connecting Rods (Cont.) 4. Crankshaft end side/thrust clearance, measure and compare to specifications (Figure 22). Connecting Rod Large End Axial Clearance Standard 0.0177-0.0374 in. Service Limit 0.0413 in. 5. Connecting rod large end oil clearance (radial) a. Clean all oil from the crankshaft rod journal and thrust side. b.
ENGINE INSPECTION AND RECONDITIONING Lower End Inspection and Reconditioning (Cont.) Oil Pump 1. Inspect the gerotor inner and outer for damage; chips, scuffs or broken gear (Figure 23). E A B D C Figure 23 A. O-Ring B. Inner Rotor C. Oil Pump Shaft D. Outer Rotor E. Oil Pump Cover 2. Inspect the oil pump shaft for wear. 3. Inspect for scuffing between the gerotor and cover. NOTE: Replace oil pump assembly if damaged. 4. Inspect cover plate for warpage. Inspection NOTE: Replace cover if warped.
ENGINE INSPECTION AND RECONDITIONING Lower End Inspection and Reconditioning (Cont.) Sump Cover 1. Clean and inspect gasket surface for nicks and deep scratches. 2. Remove and discard the crankshaft oil seal. 3. Inspect and measure the lower crankshaft bearing. -Inspect surface for wear, pitting and scratches -Measure and compare to specifications. Sump Cover Crankshaft Hole Diameter Standard 1.5751-1.5758 in. (40.009-40.025 mm) Service Limit 1.5778 in. (40.075 mm) 4.
ENGINE INSPECTION AND RECONDITIONING Lower End Inspection and Reconditioning (Cont.) Governor Assembly 1. Inspect the gear for wear or damage. 2. Inspect the weights and spool for free movement. 3. Measure end play clearance between the washer and housing. 4. Measure and compare to specifications, governor end play 0.05 in. (0.35 mm) (Figure 25). C A B D Figure 25 A. Spool B. Shaft C. Gear w/Fly Weights D. Anchored Washer Mounting Hardware Inspection 1. Clean threads of all removed hardware.
ENGINE ASSEMBLY Table of Contents Upper Assembly 1 Exploded View.................................................................................... 9-2 Upper Assembly 2 Exploded View.................................................................................... 9-3 Lower Assembly 1 Exploded View.................................................................................... 9-4 Lower Assembly 2 Exploded View....................................................................................
ENGINE ASSEMBLY Upper Assembly 1 A T O Q P J R N M B S C D E L L F G H I Figure 1 A. Blower Shroud B. Shredder Screen C. Flywheel Fan D. Bolt E. Washer F. Flywheel G. Stator H. Lower Baffle I. Electric Starter J. Side Shroud K. Oil Drain Hose Cleat L. Ignition Coil M. Fuel Line N. Fuel Pump O. Fuel Filter P. Fuel Line Q. Vacuum Line R. Side Shroud S. Paper Element T. Foam Element NOTE: Mounting components not shown.
ENGINE ASSEMBLY Upper Assembly 2 R D E F Q A C B P G I H J M N L O K Figure 2 H. Fuel Tank Vent Line I. Air Filter Manifold J. Choke Spring K. Control Plate L. Throttle Spring M. Head Gasket N. Cylinder Head O. Valve Cover P. Alignment Pin Q. Voltage Regulator and Wire Harness R. Dipstick and Tube NOTE: Mounting components not shown. Twin Cylinder Engine Service Manual February 2017 - Digital Edition 9-3 Table of Contents Reassembly A. Flywheel Key B. Upper Seal C. Breather Assembly D.
ENGINE ASSEMBLY Lower Assembly 1 B H G A F D E E C Figure 3 A. Governor Rod B. Crankcase C. Camshaft D. Crankshaft E. Connecting Rod F. Piston (1 shown) G. Oil Filter H. Oil Filter Threaded Fitting NOTE: Mounting components not shown.
ENGINE ASSEMBLY Lower Assembly 2 A W V U B D C T S X G R E F H I J Q K P L M N O A. Oil Screen Cover B. Oil Screen C. Screen Retainer D. Rubber Oil Deflector E. Spool (Gov. Asm.) F. Retaining Ring (Gov. Asm.) G. Gear w/Fly Weights (Gov. Asm.) H. Anchored Washer (Gov. Asm.) I. Shaft (Gov. Asm.) J. Seal K. Oil Pump Shaft (Oil Pump Asm.) L. Inner Rotor (Oil Pump Asm.) M. Outer Rotor (Oil Pump Asm.) N. O-Ring O. Oil Pump Cover P. Hose Fitting Q. Oil Drain Hose Asm. R. Crankcase Cover S.
ENGINE ASSEMBLY Assemble Lower End General Steps of Internal Assembly 1. Only use components that have been previously cleaned and pass inspection see chapter 8, page 8-1. 2. Lubricate components at each assembly step, using a good clean motor oil or assembly grease. Crankshaft 1. Oil the crankshaft bearing surfaces. 2. Insert the tapered flywheel end of the crank into the crankcase. Piston Rings onto Piston 1.
ENGINE ASSEMBLY Assemble Lower End (Cont.) Piston Rings onto Piston (Cont.) 2. Stagger the ring gaps approximately 120° apart (Figure 6). Assembly: Sign Sign Put the piston ring sign facing up when assembling. Don’t wrongly assemble the top ring and the second ng. After assembling, be sure the piston can freely move. Top ring Stagger the open of the piston to piston pin hole The second ring with 120 degree. Top ring Oil ring The second ring Oil ring Figure 6 Check, refer to 3.
ENGINE ASSEMBLY Assemble Lower End (Cont.) Piston onto Connecting Rod (#1 Cylinder) 1. Gather matching components for the #1 cylinder (piston, wrist pin, two clips, connecting rod, cap and bolts) (Figure 7). Figure 7 2. Install a piston pin clip into the piston. 3. Orient the piston with the “PTO” mark pointing down (Figure 8). 4. Assemble the piston to the connecting rod with the long length rotated 90° counter-clockwise (CCW) of the PTO (circled below) (Figure 8). Figure 8 5. Insert wrist pin.
ENGINE ASSEMBLY Assemble Lower End (Cont.) Piston onto Connecting Rod (#1 Cylinder) (Cont.) 6. Install the second piston pin clip. NOTE: Rotate both clips so the ends are not in the cutout area of the piston (Figure 9). Figure 9 Twin Cylinder Engine Service Manual February 2017 - Digital Edition 9-9 Table of Contents Reassembly 7. Verify the connecting rod crank journal has the large taper facing upward when the piston “PTO” mark is downward.
ENGINE ASSEMBLY Assemble Lower End (Cont.) Piston onto Connecting Rod (#2 Cylinder) 1. Gather the matching components for the #2 cylinder. 2. Install the piston pin clip into the piston. 3. Orient the piston with the “PTO” mark pointing down. 4. Assemble the piston to the connecting rod with long length rotated 90° clockwise of the PTO. 5. Insert the pin. 6. Install the second piston pin clip. NOTE: Rotate both clips so the ends are not in the cutout area of the piston. 7.
ENGINE ASSEMBLY Assemble Lower End (Cont.) Piston and Connecting Rod Assemblies onto Crankshaft 1. Remove rod cap if not previously removed. 2. Oil the piston and rings. 3. Using a ring compressor, insert the piston assembly into the matching cylinder with the piston dome “PTO” mark pointing toward PTO end of the crankshaft (#1 piston assembly in the #1 bore, #2 piston assembly in #2 bore). 4. Push piston into the bore until the rod is at the crank journal. 5.
ENGINE ASSEMBLY Assemble Lower End (Cont.) Camshaft and Followers 1. Oil and insert the exhaust and intake followers (tappets), each into their respective holes in the crankcase. NOTE: Intake is upper, exhaust is lower. 2. Rotate the crankshaft so the timing mark points toward the camshaft location. 3. Oil camshaft bearing and lobes. 4. Rotate and insert camshaft to match the timing marks on the crankshaft (Figure 12). Figure 12 5. Verify crankshaft moves freely.
ENGINE ASSEMBLY Assemble Lower End (Cont.) Sump Cover Sub-Assembly 1. Insert check ball, spring, and retain with spring and screw. Torque cover plate screw to 89 in-lbs. (10 Nm). 2. Insert retainer, oil screen, and plate, mount with two screws. Torque oil screen cover bolts to 89 in-lbs. (10 Nm) (Figure 13). A D B C Figure 13 Twin Cylinder Engine Service Manual February 2017 - Digital Edition 9-13 Table of Contents Reassembly A. Check Ball System B. Oil Pre-Screen Assembly C. Governor Assembly D.
ENGINE ASSEMBLY Assemble Lower End (Cont.) Governor Assembly Assemble governor components (spool, shaft, and governor gear), see “Governor Assembly,” chapter 8, page 8-25. 1. Install shaft into governor gear. NOTE: Snap ring should be about a quarter inch down the shaft, not in the groove. 2. While holding the three weights, install governor spool over the shaft. 3. Verify the spool rests in the groove of each weight. 4.
ENGINE ASSEMBLY Assemble Lower End (Cont.) Sump Cover Sub-Assembly (Cont.) 5. Insert the remaining components onto the sump cover (if removed) (Figure 15). -oil deflector -oil drain plug -oil drain hose and fittings Figure 15 Twin Cylinder Engine Service Manual February 2017 - Digital Edition 9-15 Table of Contents Reassembly 7. Torque the oil drain plug or hose fitting to 19 ft-lbs. (26 Nm).
ENGINE ASSEMBLY Assemble Lower End (Cont.) Sump Cover 1. Install both alignment pints into the crankcase. 2. Install the gasket and two o-rings. NOTE: The o-rings provide additional sealing for the pressure lubrication system. 3. Slide the sump cover over the crankshaft until against gasket and crankcase. NOTE: Rotate the crankshaft slightly to assist assembly. DO NOT use bolts to pull cover to crankcase. 4. Install the bolts loosely.
ENGINE ASSEMBLY Assemble Lower End (Cont.) Oil (Gerotor) Pump 1. Install the oil pump shaft (double “D” end into the end of camshaft) (Figure 17). E A B D C Figure 17 A. O-Ring B. Inner Rotor C. Oil Pump Shaft D. Outer Rotor E. Oil Pump Cover 2. Install the gerotor (inner and outer) onto the shaft. 3. Install a new o-ring. 4. Install the cover plate and secure with three bolts. Twin Cylinder Engine Service Manual February 2017 - Digital Edition 9-17 Table of Contents Reassembly 5.
ENGINE ASSEMBLY Assemble Lower End (Cont.) Crank Seals (Upper and Lower) 1. Cover the end of crankshaft with a plastic bag or use a seal protector (Figure 18). Figure 18 2. Carefully install both upper and lower crank seals. NOTE: Proper depth is just below flush. Oil Filter 1. Install the new oil filter onto the filter adapter and turn the oil filter clockwise until the rubber gasket contacts the crankcase. Tighten the oil filter an additional 1/2 - 3/4 turn. 2. Torque oil filter to 106 in-lbs. (12 Nm).
ENGINE ASSEMBLY Assemble Upper End Cylinder Head Sub-Assembly WARNING Use protective eye wear when assembling the valves. 1. Installation of valves (Figure 19) - Match valves and components to each cylinder head. - Lubricate valve stem. - Insert valve (L) into head (F). - Install valve spring seat (K). - Oil and install valve seal (J). - Install valve spring (I). - Install valve spring retainer (H). - Using a valve spring compressor, install the two valve keepers (G).
ENGINE ASSEMBLY Assemble Upper End Cylinder Heads 1. Install the two locater pins for each head. 2. Install a new head gasket. 3. Place head onto locater pins and hold. 4. Loosely install the five head bolts (three longer, two shorter), refer to Figure 20 and 21, page 9-21. 5. Tighten bolts in three passes following torque sequence and specification.
ENGINE ASSEMBLY Assemble Upper End (Cont.) Toro Twin Engine Head Cylinder Heads (Cont.) 6. Torque cylinder head bolts (50 and 70 mm) to 39 ft-lbs. (52.5 Nm) (Figure 20 and 21). Short Short Toro Twin Engine Head Figure 20 Short Short Figure 21 Sequence for Tightening: First Pass 15 ft. lbs. Mid-Point 25 ft. lbs. Final Torque 39 ft. lbs. NOTE: Be sure ball end fits into end of follower. 8. Repeat for other head.
ENGINE ASSEMBLY Assemble Upper End (Cont.) Cylinder Heads (Cont.) 7. Adjust valve clearance (Figure 22): - Rotate engine until piston is at TDC (top dead center) on compression stroke. - Rotate the rocker to fit the short end over push-rod. - Using a feeler gauge between the valve stem and the rocker, tighten the pivot nut to obtain proper clearance. NOTE: Be careful to not open valve while adjusting pivot nut. Valve Clearance (cold) - Intake 0.004-0.006 in. (0.10-0.
ENGINE ASSEMBLY Assemble Upper End (Cont.) Cylinder Heads (Cont.) 13. Torque valve cover bolts to 89 in-lbs. (10 Nm) (Figure 23). A C D B Figure 23 Torque Sequence A-D: First Pass 45 in-lbs. (5 Nm) Final Torque 89 in-lbs. (10 Nm) 14. Set gap to 0.030 in. (0.7-0.8 mm) and install the new spark plug. 15. Torque the spark plug to 21 ft-lbs. (28.5 Nm). Twin Cylinder Engine Service Manual February 2017 - Digital Edition 9-23 Table of Contents Reassembly NOTE: Repeat for the #2 cylinder head assembly.
ENGINE ASSEMBLY Assemble Upper End (Cont.) Breather 1. Install the breather reed with the reed toward the engine block (Figure 24). Figure 24 2. Torque bolt to 89 in-lbs. (10 Nm). 3. Install the breather sponge. 4. Install the new gasket and cover, secure with four bolts. 5. Torque the breather plate bolts to 89 in-lbs. (10 Nm).
ENGINE ASSEMBLY Assemble Upper End (Cont.) Intake Manifold with Engine Wire Harness and Voltage Regulator NOTE: If replacing the intake manifold only, see “Dipstick Tube (Voltage Regulator Mounted),” chapter 9, page 26 step for voltage regulator and wire harness installation, wire harness placement and anchor locations on the manifold (Figure 25). Figure 25 1.
ENGINE ASSEMBLY Assemble Upper End (Cont.) Dipstick Tube (Voltage Regulator Mounted) 1. Install the voltage regulator to the dipstick tube if previously removed (Figure 27). Figure 27 2. Torque the voltage regulator/dipstick tube bolts to 62 in-lbs. (7 Nm). 3. Install new o-ring on dipstick tube. 4. Loosely install the dipstick tube assembly into the engine block. 5. Orient the wire harness and engine harness plug around the dipstick tube, between it and the engine block. 6.
ENGINE ASSEMBLY Assemble Upper End (Cont.) Stator (Alternator) 1. Install the stator with the wire harness toward the dipstick tube and engine block (Figure 28). Figure 28 2. Secure stator with the four bolts. 3. Torque the stator charging coil bolts to 89 in-lbs. (10 Nm). 4. Route the stator wire between the dipstick tube and engine block, slide the harness into the retainer on the dipstick tube. Twin Cylinder Engine Service Manual February 2017 - Digital Edition 9-27 Table of Contents Reassembly 5.
ENGINE ASSEMBLY Assemble Upper End (Cont.) Lower Baffle 1. Place the lower baffle on the engine block while holding the stator wires in recess of the crankcase (Figure 29). Figure 29 NOTE: Do not pinch the stator or harness wires. 2. Install with four bolts. 3. Torque the baffle, cylinder shoulder bolts to 89 in-lbs. (10 Nm). 4. Loosely mount the dipstick tube to the lower baffle with shoulder bolt.
ENGINE ASSEMBLY Assemble Upper End (Cont.) Flywheel 1. Clean the taper of crank and flywheel ID taper. 2. Install the flywheel key into the slot on crankshaft taper (Figure 30). Correct Incorrect Make sure key is installed correctly Figure 30 NOTE: Long flat of key should be parallel to the length of the crankshaft, not parallel to taper of crankshaft (Figure 31). 3. Install the flywheel onto the crankshaft aligning the keyway and not contacting the stator coils under the flywheel.
ENGINE ASSEMBLY Assemble Upper End (Cont.) Flywheel (Cont.) 4 Install the flywheel compression washer cup side toward the flywheel. 5. Install and torque the flywheel nut to 61 ft-lbs. (82.5 Nm). NOTE: Use a strap wrench to hold flywheel. 6. Plastic coolant fan (Figure 32) - Align two guide pins of the fan to match the holes in the flywheel. - Install the coolant fan with four bolts. - Torque flywheel cooling fan bolts to 16 ft-lbs. (22.5 Nm). Figure 32 7. Install the fan screen with four screws. 8.
ENGINE ASSEMBLY Assemble Upper End (Cont.) Ignition Coils 1. Install the ground wire to male terminal on ignition coil (Figure 33). Figure 33 2. Install the ignition coil and loosely mount with two screws. 3. Rotate the flywheel to align magnets to ignition coil. 4. Using proper thickness gauge, tighten the ignition coil screws. Ignition coil air gap is 0.011 in. (0.3 mm). NOTE: Use caution as the magnet will strongly pull the ignition coil to the flywheel. 5. Torque the ignition coil bolts to 89 in-lbs.
ENGINE ASSEMBLY Assemble Upper End (Cont.) Electric Starter 1. Install the electric starter with two mounting bolts (Figure 34). Figure 34 NOTE: One bolt has the engine lift hook, place this bolt on the left side of the electric starter with the loop toward left, not up. 2. Torque the starter motor bolts to 19 ft-lbs. (26 Nm).
ENGINE ASSEMBLY Assemble Upper End (Cont.) Throttle/Choke Control Plate 1. Hook the choke spring to the control plate and choke arm on the control plate if previously removed (Figure 35). Figure 35 NOTE: Choke spring is 2.44 on. (61.98 Nm) long with coils compressed, throttle spring is 1.64 in. (41.66 Nm) long with coils compressed. 2. Hook the governor spring to hole “C” of governor arm and to throttle pivot on the control plate (Figure 36). Figure 36 4.
ENGINE ASSEMBLY Assemble Upper End (Cont.) Carburetor NOTE: Complete disassembly, inspection, and assembly, chapter 3, page 3-1. 1. Install the gasket, spacer, and gasket onto the intake manifold studs. 2. Slide the carburetor onto the intake manifold studs. 3. Route fuel solenoid wire up and under the intake manifold. Connect the fuel solenoid wire into the wire harness (Figure 37). Figure 37 4.
ENGINE ASSEMBLY Assemble Upper End (Cont.) Carburetor (Cont.) NOTE: Choke link is longer and has multiple bends. 5. Install throttle link to throttle pivot on the control plate, then insert into the throttle shaft on the carburetor, lock by rotating the clip over link (Figure 39). Figure 39 Twin Cylinder Engine Service Manual February 2017 - Digital Edition 9-35 Table of Contents Reassembly NOTE: Throttle link is shorter, with no bends.
ENGINE ASSEMBLY Assemble Upper End (Cont.) Air Filter Manifold 1. Install the gasket onto the intake manifold studs (Figure 40). 2. Install the air filter manifold onto the intake manifold studs. NOTE: Slide the breather vent hose (A) (Figure 40) over the fitting on #1 head while installing the manifold. B A Figure 40 3. Retain manifold with four nuts. 4. Torque the intake manifold bolts to 89 in-lbs. (10 Nm). 5.
ENGINE ASSEMBLY Assemble Upper End (Cont.) Engine Shrouds 1. Install the cylinder #2 plastic shroud. 2. Install the oil drain hose cleat if previously removed. 3. Torque the oil drain hose cleat bolts to 62 in-lbs. (7 Nm). 4. Loosely install the two longer shoulder bolts to the upper mount. 5. Install the short shoulder bolt to the underside of the head. 6. Torque the shroud mount bolts to 89 in-lbs. (10 Nm). 7. Install the cylinder #1 plastic shroud. 8. Install the fuel pump assembly if previously removed.
ENGINE ASSEMBLY Assemble Upper End (Cont.) Engine Shrouds (Cont.) 20. Slide end of the hose onto the fitting of the blower shroud (Figure 42). Figure 42 Air Cleaner Filter 1. Install the new air filter (Figure 43).
Resi dent i alPr oduct s
