RESIDENTIAL PRODUCTS WALK BEHIND MOWER ENGINE SERVICE MANUAL 2012 and Prior LC1P65FA (159cc)
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. An electronic version of this service manual is available on the Toro Dealer Portal.
Chapter 1 – General Service Information 1 Chapter 2 - Engine Service / Maintenance 2 Chapter 3 - Engine Disassembly and Service 3 Chapter 4 - Electrical 4
NOTES:
Chapter 1 – General Service Information Safety Service Rules Engine Model / Serial Number Location Engine Fastener Torque Specification General Specifications Engine Specifications Troubleshooting 1 2 3 3 4 4 5 6 1
Safety Safety 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 engine. The Toro mower and operator’s manuals contain safety information and operating tips for safe operating practices.
1 Service Rules 1. Only use genuine Toro parts and lubrication products. 2. Always install new gaskets, O-rings and seals when assembling engine. 3. Always torque fasteners to specification and in sequence. 4. Always lubricate friction components with clean engine oil or engine assembly lube when assembling engine. Engine Model / Serial Number Location The engine model and serial number are stamped into the crankcase, near the fuel tank.
Engine Fastener Torque Specifications Item Torque Fastener Size Specification Cylinder Head Bolts M8 25 ft-lbs (34 Nm) Connecting Rod Bolts M7 9.5 ft-lbs (13 Nm) Flywheel Nut M14 62.5 ft-lbs (85 Nm) Valve Adjust Lock Nut M6 10 ft-lbs (14 Nm) Pivot Arm Pivot Stud M8 22 ft-lbs (30 Nm) Crankcase Cover Bolt M6 7.5 ft-lbs (10 Nm) Muffler Nuts M6 7.5 ft-lbs (10 Nm) Air Cleaner Nuts M6 6 ft-lbs (8 Nm) Recoil (Fan Shroud) Nut M6 6 ft-lbs (8 Nm) Oil Drain Bolt M10 15.
1 Engine Specifications Part Engine Cylinder Head Item Standard Service Limit Operating RPM 2900 – 3100 RPM － Warpage － 0.00393” (0.10 mm) 2.559” (65.0 mm) 2.566” (65.165 mm) Skirt Outside Diameter 2.558” (64.985 mm) 2.553” (64.845 mm) Cylinder Clearance 0.00059 - 0.00196” (0.015-0.05 mm) 0.00472” (0.12 mm) Piston Pin Bore Inside Diameter 0.5118” (13.002 mm) 0.5137” (13.048 mm) Piston Pin Clearance 0.00007- 0.0005” (0.002-0.014 mm) .00314“ (0.08 mm) Outside Diameter 0.5118” (13.
Troubleshooting Hard Starting / Poor Running - Incorrect Fuel (Level, Age, Octane, Ethanol Content) - Fuel System Contamination and / or Carburetor Debris - Incorrect Oil Level - Spark Plug (Incorrect Gap, Fouled, Loose or Faulty) - Air Filter Restriction - Air Intake System Leaks - Ignition Coil to Flywheel Gap Incorrect - Weak / No Spark - Auto Choke System (Improper Function) - Choke / Air Vane Linkage - Operating RPM Incorrect - Governor Adjustment Incorrect - Engine Valve Clearance out of Specification
Chapter 2 - Engine Service / Maintenance Engine Oil Change Procedure Air Cleaner Service Spark Plug Service Valve Clearance Inspection and Adjustment Engine Governor – Zero Point Setting Fuel Filter Replacement Auto Choke System / Function Auto Choke System View 7 8 9 10 11 11 12 13 14 2
Engine Oil Change Procedure 1. Run engine to warm engine oil. 2. Remove spark plug cap from the spark plug. NOTE: Ensure fuel system contains no fuel to prevent leakage when the mower is tipped onto its side. 3. Remove the dipstick. 4. Tip the mower onto side with the dipstick on the downward side. Drain the used oil through the oil fill tube into a suitable container. 5. Return the mower to the operating position. 6. Add oil through the dipstick tube.
2 Air Cleaner Service 1. Press the upper latch tabs and rotate the top of the cover outward to open and remove the cover. 2. Remove the paper air filter and the foam pre-filter. 3. Inspect the foam pre-filter, and replace it if damaged or excessively dirty. 4. Inspect the paper air filter. NOTE: If the paper air filter is excessively dirty, damaged or is wet with oil or fuel, replace it. 5. Remove dirt from the air cleaner body and cover using a moist rag. Do not wipe dirt into the air duct.
Spark Plug Service NOTE: Spark plugs of the wrong size or incorrect heat range can cause severe engine damage. High Voltage Ignition Systems can be Dangerous - Use Caution when Servicing Ignition Systems 1. Disconnect the spark plug cap and thoroughly clean the spark plug area. 2. Remove the spark plug from the engine. 3. Inspect the spark plug for excessively worn electrodes, chips or cracks in the insulator, or excessive deposits. 4. Measure the electrode gap and adjust if necessary. Spark Plug Gap: 0.
2 Valve Clearance Inspection and Adjustment NOTE: Valve clearance inspection and adjustment must be done with the engine cold. 1. Rotate engine to TDC (top-dead-center) of the compression stroke. 2. Remove the valve cover. Be sure both valves are completely closed and the decompression arm is not holding the valve open. 3. Measure the clearance between the rocker arm and the valve stem with a feeler gauge. Intake: 0.0039” (0.10 mm) Exhaust: 0.0059” (0.15 mm) 4.
Fuel Filter and Hose Replacement - Fuel is Extremely Flammable - Use Extreme Caution When Servicing the Fuel System 1. Drain the fuel tank into an approved container. NOTE: Ensure fuel system contains no fuel to prevent leak when the fuel filter is replaced. 2. If necessary, remove air filter cover and base as outlined in this manual. 3. Release the fuel filter / fuel hose clamps (A) and slide them away from fittings. 4. Remove the fuel filter / fuel hose asm. from the engine. 5.
2 Auto Choke System / Function A. Governor Rod - Connected to the governor system which controls the angle of the throttle plate and sets engine operating RPM. B. Thermal Spring Rod - Connected to the thermal spring, which mounts on the muffler. The thermal spring adjusts the choke plate angle as the engine temperature changes. C. Air Vane Rod - Connected to the air vane in the blower housing which will fully open the choke plate at full operating RPM at any engine temperature.
Auto Choke System View Washer Screw Air Vane Thermal Spring Asm.
Chapter 3 - Engine Disassembly and Service Engine Service – Upper End 16-26 Air Cleaner and Muffler Exploded View Recoil Starter and Engine Cover Exploded View Carburetor and Linkage Exploded View Flywheel and Breather Exploded View and Service Info Cylinder Head Exploded View and Service Info Intake and Exhaust Valve Exploded View and Service Info Valve Spring / Valve Seat / Cylinder Head Specifications Valve Stem / Valve Guide Specifications Valve Seat Reconditioning 16 17-18 19-20 21 22 23 24 25 26
Engine Service – Upper End Air Cleaner and Muffler Exploded View Nut Muffler Shield Muffler Exhaust Gasket Breather Tube Intake Gasket Air Cleaner Base Primer Asm (International Only) Nut Paper Element Foam Element 16 Cover
3 Recoil Starter and Engine Cover Exploded View Screw Engine Cover Recoil Asm.
Recoil Asm.
3 Carburetor and Linkage Exploded View Control Asm.
Carburetor Exploded View Throttle Valve Asm.
3 Flywheel and Breather Exploded View and Service Info Flywheel Nut 63 ft-lbs (85 Nm) 6 ft-lbs (8Nm) Breather Cover Shield 7.5 ft-lbs (10Nm) Breather Gasket Breather Valve Key Brake / Switch Asm.
Cylinder Head Exploded View and Service Information Cylinder Head Gasket Spark Plug 22 ft-lbs (36 Nm) 7.5 ft-lbs (10 Nm) Valve Cover Gasket Valve Cover Cylinder Head Bolt Torque Sequence: 1. Initially Torque the (4) Cylinder Head Bolts in a Crisscross Pattern to 10 ft-lbs (14 Nm). 2. Evenly Torque the (4) Cylinder Head Bolts in a Crisscross Pattern to 25 ft-lbs (34 Nm).
Intake and Exhaust Valve Exploded View and Service Information Rocker Arm Pivot Stud 22 ft-lbs (30 Nm) 3 Push Rods Rocker Arm Lock Nut 11 ft-lbs (15 Nm) Intake Valve Push Rod Guide Rocker Arm Pivot Valve Spring Retainer Exhaust Valve Valve Spring 23
Valve Spring Free Length Specification Standard Service Limit 1.2007” (30.5 mm) 1.1417” (29.0 mm) NOTE: If this measurement is out of specification, complete engine replacement is required. The only internal parts available for this engine are gaskets and seals. Valve Seat Width Inspection Remove carbon deposits from the combustion chamber. Inspect the valve seats for pitting or other damage. Valve Seat Width Specification: Standard Service limit 0.0314” (0.8 mm) 0.0787” (2.
3 Valve Stem Inspection Inspect each valve for face irregularities, bending or abnormal wear. Valve Stem Diameter Specification Standard Service Limit Intake 0.2157” (5.48 mm) 0.2093” (5.318 mm) Exhaust 0.2141” (5.44 mm) 0.0047” (0.12 mm) NOTE: If this measurement is out of specification, complete engine replacement is required. The only internal parts available for this engine are gaskets and seals.
Valve Seat Reconditioning 1. Thoroughly clean the combustion chamber and valve seats to remove carbon deposits. 2. Apply a light coat of Prussian Blue or erasable felt-tipped marker ink to the valve faces. 3. Properly install valves, springs and keepers. Manually open the valves, then and snap them closed against their seats several times. Be sure the valves do not rotate on the seat. Remove the valve assemblies. The transferred marking compound will show any area of the seat that is not concentric. 4.
Engine Service – Lower End 3 Crankcase / Governor Exploded View and Service Information Governor Exploded Views Governor Asm. 7.5 ft-lbs (10 Nm) Gasket Aux. Oil Drain 15.
Crankcase Exploded View Oil Dip Stick Oil Seal Governor Arm Shaft Governor Lock Pin Governor Oil Seal O Ring 6 Sump Cover Gasket 1 Crankcase / Sump Cover 3 4 Oil Seal 7 2 5 Crankcase / Sump Cover Bolt Torque Sequence 7.
3 Crankshaft / Piston / Camshaft Exploded View and Service Info Oil Seal Bearing Cam Shaft Valve Tappets Piston Asm. Connecting Rod Bolts 9.
Piston Connecting Rod Exploded View and Service Information Assembly: Mark Install Rings with Orientation Mark “UP” Stagger the piston ring gap as shown: Top Ring Second Ring Top Ring Oil Ring Second Ring Oil Ring Check, refer to Piston Piston Pin Piston Pin Circlip: Install the circlip gap in the 12:00 Position (circlip gap facing up) Connecting Rod Orientation Align Long end of connecting rod CLIP with piston orientation “triangle” CUT-OUT 30
3 Valve Timing Crankshaft Timing Marks Crankshaft Bearing Free Play 1. Clean the bearing in solvent and dry it. 2. Spin the bearing by hand and check for play. Replace the bearing if it is noisy or has excessive free play.
Crankshaft Bearing Free Play 1. Clean the bearing in solvent and dry it. 2. Spin the bearing by hand and check for play. Piston Pin Outside Diameter Standard Service Limit 0.5118” 0.51” (13.0 mm) (12.954 mm) NOTE: If this measurement is out of specification, complete engine replacement is required. The only internal parts available for this engine are gaskets and seals. Cylinder Taper and Out of Round Inspect cylinder for taper and out of round with a bore gauge.
Piston Skirt Outside Diameter Measure the piston skirt outside diameter 10mm from the skirt base and 90°to piston pin hole. Standard Service Limit 2.558” 2.553” (64.985 mm) (64.845 mm) NOTE: If this measurement is out of specification, complete engine replacement is required. The only internal parts available for this engine are gaskets and seals. Piston to Cylinder Clearance Specification Standard Service Limit 0.00059 - 0.00196” 0.00472” (0.015-0.05 mm) (0.
Piston Ring End Gap Standard Service Limit 0.0078 - 0.0157” 0.0393” (0.2-0.4 mm) (1.0 mm) Use the piston to position the rings squarely 1” down from the top of the cylinder. NOTE: If this measurement is out of specification, complete engine replacement is required. The only internal parts available for this engine are gaskets and seals. Connecting Rod Small End ID Standard Service Limit 0.5125” 0.5145” (13.02 mm) (13.
Crankshaft pin OD Standard Service Limit 1.0228” 1.0204” (25.98 mm) (25.92 mm) NOTE: If this measurement is out of specification, complete engine replacement is required. The only internal parts available for this engine are gaskets and seals. Connecting Rod Big End Side Clearance Standard Service Limit 0.00393 - 0.02755” 0.0433” (0.1-0.7 mm) (1.1 mm) NOTE: If this measurement is out of specification, complete engine replacement is required.
Camshaft Lobe Specifications Standard Service Limit 1.0905” 1.0807” (27.7 mm) (27.45 mm) 1.0925“ 1.0826” (27.75 mm) (27.50 mm) Intake Exhaust NOTE: If this measurement is out of specification, complete engine replacement is required. The only internal parts available for this engine are gaskets and seals. Camshaft Journal OD Standard Service Limit 0.5505” 0.5478” (13.984 mm) (13.916 mm) Check the camshaft bearing journal for scoring, wear or damage.
Chapter 4 – Electrical System Information Ignition / Charge Coil Gap Adjustment Ignition Coil Resistance Inspection Spark Testing Electrical System Wiring 38 38 39 40 37 4
Ignition / Charge Coil Gap Adjustment High Voltage Ignition Systems can be Dangerous - Use Caution when Servicing Ignition Systems 1. Install the coil and lightly tighten the mounting bolts. 2. Rotate engine so the coil is aligned with the magnet portion of the flywheel. 3. Insert the feeler gauge between the flywheel and coil. 4. Adjust the coil gap at both side of the coil. 5. Torque the coil mounting bolts to specification – 7.5 ft-lbs (10 Nm). Ignition / Charge Coil Gap .01” (0.
4 Spark Testing - Fuel is Extremely Flammable - Use Extreme Caution When Servicing the Fuel System - High Voltage Ignition Systems can be Dangerous - Use Caution when Servicing Ignition Systems 1. Safely drain the fuel system and store fuel in an approved container. 2. Remove spark plug boot from the spark plug. 3. Remove the spark plug from the engine. 4. Connect the negative (-) electrode of the spark plug (threaded area) to ground (cylinder head cover). 5. Crank the engine and view the electrode gap.
Electrical System Wiring (Electric Start Shown) A Ignition Coil B Starter Motor C Alternator D Brake / Kill Switch E Starter Interlock Switch F To Chassis Harness G To Ground A B D G E C F F 40
NOTES: 41
RESIDENTIAL PRODUCTS Form Number: 492-9231 42
