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AC-1 ENGINE SERVICE MANUAL

Table of Contents – Page 1 of 2

ABOUT THIS MANUAL

GENERAL INFORMATION

ENGINE SPECIFICATIONS

FUEL AND LUBRICATION

IGNITION

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS (CONT)

SAFETY WARNINGS AND NOTES

PRODUCT IDENTIFICATION NUMBERS

OIL AND FUEL RECOMMENDATIONS

STARTING/STOPPING INSTRUCTIONS

SERVICE/MAINTENANCE INSTRUCTIONS

STORAGE INSTRUCTIONS

TROUBLESHOOTING

ENGINE FAILS TO START

ENGINE STARVES ON ACCELERATION

ENGINE IS HARD TO START

ENGINE STALLS

ENGINE FIRES INTERMITTENTLY

ENGINE DOES NOT PRODUCE MAXIMUM POWER

CARBURETOR FLOODS

ENGINE STOPS AFTER RUNNING BRIEFLY

ENGINE WILL NOT IDLE

ENGINE BACKFIRES OR MISFIRES

ENGINE WILL NOT ACCELERATE

ENGINE LACKS POWER OR STOPS DURING OPERATION

ENGINE VIBRATES EXCESSIVELY

ENGINE USES EXCESSIVE AMOUNT OF OIL

STARTER ROPE IS DIFFICULT TO PULL OR ENGINE LOCKS

DISASSEMBLY

TYPICAL DISASSEMBLY SEQUENCE

REMOVE MAJOR COMPONENTS

DISASSEMBLE ENGINE

INSPECTION AND REPAIR

CARBURETOR DISASSEMBLY AND REASSEMBLY

STARTER DISASSEMBLY AND REASSEMBLY

BREATHER DISASSEMBLY AND REASSEMBLY

SPARK ARRESTER SCREEN

PISTON/CONNECTING ROD DISASSEMBLY & ASSEMBLY

CYLINDER HEAD INSPECTION & REPAIR

Summary of Contents for AC-1

Page 1: ...RMITTENTLY ENGINE DOES NOT PRODUCE MAXIMUM POWER CARBURETOR FLOODS ENGINE STOPS AFTER RUNNING BRIEFLY ENGINE WILL NOT IDLE ENGINE BACKFIRES OR MISFIRES ENGINE WILL NOT ACCELERATE ENGINE LACKS POWER OR STOPS DURING OPERATION ENGINE VIBRATES EXCESSIVELY ENGINE USES EXCESSIVE AMOUNT OF OIL STARTER ROPE IS DIFFICULT TO PULL OR ENGINE LOCKS DISASSEMBLY TYPICAL DISASSEMBLY SEQUENCE REMOVE MAJOR COMPONEN...

Page 2: ...age 2 of 2 INSPECTION AND REPAIR Continued CRANKCASE INSPECTION REPAIR MAJOR COMPONENTS INSPECTION REPAIR REASSEMBLY TYPICAL ASSEMBLY SEQUENCE ENGINE REASSEMBLY INSTALL AIR FILTER BASE AIR FILTER AND AIR FILTER COVER ASSEMBLE HANDLE ASSEMBLE COVERS ...

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Page 4: ...d this manual a valuable addition to your service shop If you have any questions or comments regarding the information inside please contact us at the following address The Toro Company Consumer Service Training Department 8111 Lyndale Avenue South Bloomington MN 55420 The Toro Company reserves the right to change product specifications or this manual without notice Copyright All Rights Reserved 1...

Page 5: ... General Information B 2 Troubleshooting Disassembly 4 InspectionandRepair 5 Reassembly ...

Page 6: ... Use of Fuel Additives 1 3 1 4 1 4 1 4 1 6 1 7 1 7 1 7 1 8 1 9 1 9 1 9 1 9 1 9 Starting stopping Instructions 1 10 To StarttheEngine 1 10 To StoptheEngine 1 11 Service maintenance Instructions 1 11 AirFilter 1 11 Spark Plug 1 12 Carburetor Adjustment 1 12 HighSpeedMixtureAdjustments 1 15 RockerArmtoValveClearanceAdjustment 1 15 SparkArresterScreen 1 16 Storage instructions 1 17 To Reactivate Unit ...

Page 7: ...s Side Clearance Top Piston Ring Width Top Piston Ring End Gap Middle Piston Ring Width Middle Piston Ring End Gap Oil Piston Ring Width Oil Piston Ring End Gap Rocker Armto Valve Clearance B _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _____ _ _ __ _ Air cooled 4 Cycle 1 3 ...

Page 8: ...buretor Air Filter Base Plate Mounting Screws Carburetor Mount Insulator Screws Clutch Housing Drum Assembly Screws Clutch Rotor Cylinder Head Hex Nuts Cylinder Screws Spark Plug Rear Engine Cover Screw Front Engine Cover Screws _ _ _ _ _ _ _ _ _ __ _ _ ____ ___ __ 1 4 ...

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Page 10: ...ase trimmer cutting head and other engine surfaces get extremely hot from op eration These surfaces remain hot for a short period of time after the engine is stopped To prevent severe burns allow the engine to cool completely before serv icing I WARNING Explosive Fuel Gasoline may be present inthe fuel tank carburetor fuel lines or crankcase Gasoline is extremely flamma ble and its vapors can expl...

Page 11: ...ith hot parts or sparks from Ignition Do not start the enginenear spilledfuel Donot smoke while handlinggasoline Never use gasoline as a clean ing agent can explode if ignited Store gasoline only in ap NOTE READTHESEINSTRUCTIONS CAREFULLY BEFOREAttempting TO START OR OPERATE THIS UNIT Using old oil or fuel can cause engine damage This type of damage will void the engine warranty RecommendedOil Typ...

Page 12: ...ft Unit 3 6051 004 2 To keep dirt grass clippings etc out of the engine clean the area around the oil fill plug before remov ing it 3 Remove theoil fill plug wipe theoil off Reinsert it into the crankcase Thread the oil fill plug into the oil pan 4 Remove theoil fill plug and check the oil level Figure 1 5 1 8 Figure 1 5 Removing Oil FillPlug 2 6051 005 The oil level should be up to the top of the...

Page 13: ...tom of the dipstick Recommended Fuel Type Use clean fresh regular grade unleaded gasoline less than 60 days old NOTE Alcohol blended fuel absorbs moisture water As little as 1 moisture in the fuel can cause fuel to separate and form acids when stored Ifthese types of fuel must be used use fresh fuel less than 60 days old Definitionof Blended Fuels Today s fuels are often a blend of gasoline and on...

Page 14: ...ulb5 to 7 times Figure 1 9 NOTE For a warm engine go directly to step 5 place the choke lever directly inthe PARTIAL choke position 3 Place the choke lever inthe FULL CHOKE posi tion Figure 1 9 Run position choke Partial Choke Figure 1 9 PrimerBulb ChokeLeverandChoke Positions 3 6051 009 4 With the unit on the ground pull the starter rope quickly until the engine sounds like it wants to run no mor...

Page 15: ...E CLEAN ANDRE OILTHE AIR FILTER EVERY 10 HOURSOF OPERATION The air filter is one of the most important areas to maintain If it is not maintained as follows poor engine performance and severe engine damage can result 1 Remove the three 3 screws on the carburetor air filter cover assembly Remove the air filter cover and air filter Refer to Part 3 Engine Disassembly 2 Wash the air filterin detergent ...

Page 16: ...is badly burnt or if reuse is questionable 1 12 NOTE Donotcleanthesparkplug in amachine which uses abrasive grit Some grit could remain on the spark plug and enter the engine causing extensive damage 4 Check the spark plug gap using a wire feeler gauge Set the gap to 0 025 in 0 635 mm Figure 1 14 5 Reinstall the spark plug and torque to 100 110 in lb 1 1 3 1 2 3 N m Figure 1 14 Spark Plug Gap 3 60...

Page 17: ...structions 1 Initial Idle Speed Setting Turn the idle speed screw untilit stops 2 Initial High Speed Mixture and Idle Speed Mix ture Settings Turn both the high speed mixture and idle mixture needles in clockwise until they are lightly seated 3 Turntheneedles o u t the following numberof turns High Speed Mixture Needle 1 turn Idle Speed Mixture Needle 1 turn NOTE Turn the high speed mixture and id...

Page 18: ... Turn both the high speed mix ture and idle speed mixture needles in clock wise until they are lightly seated 1 14 3 Turn the needlesout counterclockwise the following number of turns High Speed Mixture Needle 1 1 8 turns Idle Speed Mixture Needle1 1 8 turns NOTE Seat the high speed mixture and idle speed mixture needles using finger pressure Forcing the mix ture needles will damage the tips of th...

Page 19: ...ing needle in clockwise The en gine speed may increase as the needle isturned in lean Note the position of the needle 3 Set the adjusting needlemidway between the rich and the lean settings Figure 1 16 Midpoint Adjust to Lean I Figure 1 16 Optimum Setting 3 6051 016 Rocker Armto Valve Clearance Adjustment Every 50 hours of operation remove therockerarm cover and check the rocker arm to valve clear...

Page 20: ...ngine cover and screws Refer to Part5 Engine Reassembly Torque the top screws to 15 20 in lb 1 7 2 2 Nom Torque the front screw to 20 25 in lb 2 2 2 8 Nom Torque the rear screw with washer to 30 35 in lb 3 5 4 0 Nom Spark Arrester Screen This unitis equipped with a spark arrester screen Every 50 hours of operation check the spark arrester screen for debris and or deposits WARNING Hot Surfaces Make...

Page 21: ...Pull the starter rope a few times to lubricate the engine 4 Allow the engine to cool Remove the spark plug and put several drops of any high quality SAE30 weight oil of API American Petroleum Institute service class SG SF SH into the cylinder Pull the starter rope slowly to dis tribute the oil Reinstall the spark plug 5 Clean the unit and inspect for any loose or damaged parts Repair or replace da...

Page 22: ...918 Figure 1 22 FlywheelHoldingTool P N180919 Figure1 23 0 250in lb 0 28 1 N m TorqueWrench Toro R Screwdriver or Bit Set Commercially Commercially available available Two stroke MagneticPick upTachometer Commercially available Figure 1 22 Clutch RotorTool P N 180918 3 6051 022 1 18 Figure 1 23 Flywheel Holding Tool P N 18091 9 3 6051 023 f f f ...

Page 23: ...General Information Troubleshooting Disassembly InspectionandRepair Reassembly 1 2 5 2 1 ...

Page 24: ... 5 EngineDoesNotProduceMaximumPower 2 6 Carburetor Floods 2 6 EngineStopsAfterRunningBriefly 2 7 Engine Will NotIdle 2 7 EngineBackfires Or Misfires 2 7 EngineWillNotAccelerate 2 8 EngineLacksPowerOrStopsDuringOperation 2 8 Engine Vibrates Excessively 2 9 EngineUsesExcessiveAmountOf Oil 2 9 Starter Rope Is DifficultTo Pull Or Engine Locks 2 9 2 2 ...

Page 25: ... pump passages Incorrect air gap between flywheel ignition module _ _ _ _ _ __ ____ _____ ____ _ _ __ Faulty ignition module Low compression Rocker arm to valve clearance is out of adjustment _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ___ _ _ _ _ _ _ _ _ _ _ i __ __ _ _ Remedy Place switchin RUN I position Drain tank and blow out fuel lines to remove water Refuel tank with fresh fuel Clean or replace air fil...

Page 26: ...phragm Faulty fuel pump diaphragm Low compression _ _ _ _ _ _____ ________ __ __ _ ___ 2 4 1 Remedy Clean or replace spark plug Replace fuel filter Adjust carburetor set gap to 0 025 inch 0 635 mm _ _ _ _ _ Clean or replace muffler Correctly install primer fuel lines or replace primer Set ignition module air gap to 0 008 0 012 in 0 201 0 305 mm Replace ignition module Clean or replace spark arrest...

Page 27: ...ion module improperly adjusted carburetor Faulty ignition module Clean or replace spark plug set gap to 0 025inch 0 635 mm Clean fuel tank cap vent Adjust carburetor Clean or replace muffler Clean or replace spark arrester screen Blow out fuel line Replace ignition module _ _ _ __ _ _ _ ____ __ _ _ __ Remedy Clean or replace spark plug set gap to 0 025inch 0 635 mm Set ignition module air gap to 0...

Page 28: ...rburetor Air leak at carburetor base gasket Intermittent spark Low compression Scored piston and or cylinder Worn piston rings or low compression _ p _ _ __ Cam gear improperly timed Valves leaking Carburetor Floods I p p _ ulty primer or improperly installed primer fuellines _ _ 11Damaged carburetor 11Leaking fuel inlet needle 2 6 Remedy I ...

Page 29: ...__ _ _ _ ___________ __ _ _ _ _ Possible g Cause i Remedy _ _ 1 Improperly adjusted carburetor Dirty or plugged air filter Clean or e Faulty carburetor diaphragm Replace carburetor aphragm Faulty carburetor inlet seat gasket Replace carburetor inlet seat gasket Leaking crankshaft seal ace Adjust carburetor _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ __ ________ ______________ _ _ _ _ _ _ _ ____ I __ Scor...

Page 30: ...g flooding Dirty or plugged air filter Plugged muffler Plugged spark arrester screen Rocker arm to valve clearance is out of adjustment Scored cylinder or low compression below 90 psi _ _ _ _ _ _ _ _ _ _ Replace primer bulb Clean or replace air filter Clean or replace muffler Clean or replace spark arrester screen Adjust rocker arm to valve clearance I Overhaul engine _ _ _ _ _ _ _ _ _ _ _ _ _ 2 8...

Page 31: ...xcessively piston rings and or piston Piston fit and replace pistonif necessary I Replace 1 use new gaskets breather housing assembly _ _ _ smooth gasket surfaces _ _ __ ____ _ _ _ _ _ _ _ _ _ 1Measure _ _ _ _ _ _ Starter RopeIs Difficult To Pull Or Engine Locks Oilaccumulated in combustion chamber 1 Remove the spark plug 2 Drain theoil from the spark plug opening 3 Pull the starter rope several t...

Page 32: ...General Information Troubleshooting Disassembly InspectionandRepair Reassembly 1 2 3 4 5 3 1 ...

Page 33: ... 8 RemoveIntakeBaffle 3 9 Remove Muffler 3 9 Remove Clutch 3 10 RemoveStarterModuleAssembly 3 12 Remove Fuel Tank Bracket And Fuel Tank 3 13 FuelTank And Lines Disassembly And Reassembly 3 13 FuelLineandFilterRemoval 3 13 Fuel Line and Filter Installation 3 13 Disassemble Engine 3 14 RemoveFanHousing 3 14 Remove IgnitionModule 3 14 Remove Rocker Arm Assembly 3 15 Cylinder 3 17 RemoveCamBracketAsse...

Page 34: ...cation The following sequence is suggested for complete en gine disassembly This procedure can be variedtoac commodate individual requirements for disassembly Referto the appropriate parts manual to ensure the correct replacement parts are ordered 1 Drain Fuel fromTank and Oil fromOil Pan 2 RemoveSparkPlugWireandSparkPlug 3 RemoveEnginefromEquipment 4 RemoveLowerHandle 5 RemoveAirFilter 6 Remove A...

Page 35: ... engine to cool 33 Drain theoil from the oil pan 2 6051 005 Remove The Spark PlugWire And SparkPlug 1 Disconnect the spark plug wire from the spark plug Remove the spark plug Remove Upper Handle NOTE All screws are T 25 Toro R screws and can be removed with a T 25 Toro R screwdriver 1 Remove the six 6 screws from the upper handle 3 4 5 ...

Page 36: ...e switch lifted off the two pins lo cated in the lower handle 2 Remove the throttle cable and lead wires from the lower handle I REMOVE MAJOR COMPONENTS cont I 3 3 3 Press down on the lower handle at the rear near the isolator This will dislodge the isolator from the lower handle allowing the handle to be re moved I NOTE If you have difficulty removing the lower handle slightly loosen the screws o...

Page 37: ...ould be inthe PARTIAL 3 position to remove and install the air filter cover 2 Remove the air filter element from the air filter base The element is held in place by eight 8 pins Remove Air Filter Base Primer Bulb And Carburetor 1 Remove the three 3 screws securing the air filter base primer bulb and carburetor to the carbure tor mount insulator 3 6 2 6047 ...

Page 38: ... throttle cable from the carburetor mount insulator Remove PrimerBulb 1 Remove the fuel lines from the fittings on the primer bulb 2 Squeeze the mounting tabs on the back of the bulb and pull the bulb out from the front of the air filter base 3 Inspect the check valvesin the primer bulb for fuel leakage To do this inspection place your finger over the long fitting on the back of the primer bulb an...

Page 39: ... screw Remove Carburetor Mount Insulator 1 Remove thetwo 2 screws securing the carburetor mount insulator to the crankcase 3 8 3 6047 035 2 Remove thetwo 2 screws from the top of the cover and the screw from the front of the cover Lift the cover up and off of the engine 3 6047 037 ...

Page 40: ...hetwo 2 hex nuts on the back of the carburetor mount insulator NOTE ForUnitsPrior to Engine Serial Number 3 4050000001 The hex nuts were not retained Be careful not to lose them I Remove Intake Baffle 1 Remove the intake baffle from the cylinder 2 6047 039 Remove muffler 1 Remove the three 3 muffler mounting bolts 3 9 ...

Page 41: ...sket surfaces with metal scrapers Always use wood or plastic scrapers RemoveClutch 1 Remove the three 3 screws securing the clutch housing drum assembly to the fan housing Re move the clutch housing drum assembly For units that take attachments remove the spring 2 Remove the isolator which is located between the clutch cover and the starter module assembly 3 10 2 6047 043 ...

Page 42: ...P N 18091 9 4 Lift the starter assembly untilit contacts the clutch rotor At 9 o clock on the fan housing roll the fly wheel holding tool into the flywheel until the head of the cap screw on the bottom of the tool fits into the screw hole of the fan housing 5 Holding the flywheel holding tool in place postion the clutch rotor tool P N 180918 over the rotor ...

Page 43: ...ench turn the clutch rotor tool counterclockwise to remove the clutch rotor 2 6047 M 7 Remove the clutch rotor and washer Remove Starter Module Assembly 1 Remove thetwo 2 screws securing the starter rope eyelet bracket Remove the starter module assembly 3 12 ...

Page 44: ...nto the fuel tank until you can 2 If the fuel filteris dirty or clogged replaceit with a pull the filter out of the tank neck new fuel line assembly Fuel Line and Filter Installation 1 Insert a pieceof trimmer line through the hole in the rear side of the fuel tank to the filler opening Slide the fuel line over the trimmer line 2 Guide the fuel line through the hole in the tank with the trimmer li...

Page 45: ...curing the fan housingto the crankcase Remove the fan hous ing 2 Disconnecttheswitchleadwires Remove Muffler Baffle 1 Removethemufflerbaffle 53 Remove Ignition Module 1 Remove thetwo 2 screws securing the ignition moduleto the crankcase Remove the ignition module 3 1 4 ...

Page 46: ...are cracked or broken re place the flywheel 1 Removethespacerfromthecrankshaft 2 Using a plastic faced mallet tap and pull the fly wheel untilit breaks free from the crankshaft 3 Removetheflywheelfromthecrankshaft I 4 Remove the flywheel key from the crankshaft Remove Rocker Arm Assembly 1 Remove the rocker arm cover screw Remove rocker arm cover and gasket I I 3 6047 058 3 15 ...

Page 47: ... Remove thetwo 2 push rods from the push rod I NOTE Always match intake and exhaust parts when disassembling the rocker arm assembly guides 4 Remove the four 4 cylinder hex nuts and washers 5 Remove the pushrodguides from thecylinder studs 3 16 Adjusting Nut Arm Rocker Arm 2 6060 060 2 6047 061 ...

Page 48: ...emove the two 2 valves and valve retainers from the cylinder head NOTE To make removal of the valves easier push down on the valve retainers with your fingers and rock themto the side 3 Remove thetwo 2 valvesprings NOTE The valves cannot be ground Replace necessary NOTE The rocker boxis factory assembled and should not be removed from the cylinder head ...

Page 49: ...ylinder gasket from the crankcase NOTE Do not scrape the gasket from the cylinder To remove the gasket soak the cylinder with solvent Remove Piston connectingrod 1 Remove the piston connecting rod from the crank case Grasp the piston connecting rod slide it to the rear and twist slightly No toolis required 3 18 2 6047 066 ...

Page 50: ...acket assembly Remove Oil Pan 1 Remove the six 6 screws from the oil pan Re move theoil pan Remove Seal NOTE Remove the seal only if oil is leaking from he crankcase 1 Remove the seal from the flywheel side Of the crankcase using a seal puller or flathead screw driver NOTE Do not remove the crankshaft from th6 crankcase 3 19 ...

Page 51: ...General Information Troubleshooting Disassembly Inspection and Repair Reassembly I ...

Page 52: ...sterScreen 4 16 Piston ConnectingRodDisassembly Assembly 4 17 Piston Inspection and Repair 4 17 Connecting Rod Inspection and Repair 4 18 Fuel Metering Side 4 6 Final Carburetor Adjustment i 4 9 Reassembly 4 18 Cylinder Head Inspection Repair 4 19 CylinderInspectionandRepair 4 19 Crankcase Inspection and Repair 4 20 CamBracketDisassemblyandInspection 4 21 CamBracketReassembly 4 21 Major Component ...

Page 53: ...ntion should be given to commercial cleaners compatibility with plastic parts Make sure that the cleaner is wiped off of the engine parts and not allowed to air dry as some cleaners leave a residue on parts which can affect engine lubrication CARBURETOR DISASSEMBLY AND REASSEMBLY Carburetor Disassembly The fast idle starting system consists of a throttle cam whichis activated by a choke cam When t...

Page 54: ...2 Remove the fuel metering diaphragm and gasket 2 6047 074 NOTE Thesecomponentsareunderspring tension Remove them carefully to preventloss Make sure the spring is not stretched 4 4 ...

Page 55: ...creen etc is not recommended NOTE To prevent damageto the carburetor body do not use drill bits or wire to clean fuel ports and passages Carburetor Inspection and Cleaning Two carburetor service kits are available a gas ket diaphragm kit and a carburetor repair kit The gasket diaphragm kit contains the fuel metering cover gasket fuel metering diaphragm fuel pump cover gasket and fuel pump diaphrag...

Page 56: ...e to replace gaskets and diaphragms for each repair However if the diaphragmis soft and flexible you do not need to replace it un less a complete carburetor rebuild is being per formed 3 Cleanthemeteringcover pumpcover carburetor body and filter screen with carburetor cleaner Blow out all passages with compressed air Carburetor Reassembly Fuel Metering Side 1 Install the fuel inlet needle fuel met...

Page 57: ...tering lever The fuel metering lever should be 0 060 0 070 in 1 52 1 78 mm below the straight edge If the leveris adjusted too high the engine will run rich If the leveris adjusted too low the en gine will run lean Poor acceleration and erratic operation may also be noted 3 Install the metering cover gasket next to carbure tor body and metering diaphragm Make sure the larger circular plate of diap...

Page 58: ...terclockwise the following number of turns 2 6047 082 For Units with Engine Serial Number Prior to 407000001 High Speed Mixture Needle 1 turn Idle Speed Mixture Needle 1 turn For Units with Engine Serial Number 407000001 and Greater High Speed Mixture Needle 1 1 8 turns Idle Speed Mixture Needle 1 1 8 turns NOTE Turn the high speed mixture and idle mixture needles finger tight Do not force the nee...

Page 59: ... 6047 0 3 If necessary install the idle speed adjusting screw and spring For Units with Engine Serial Number 407000001 and Greater Turn the adjusting screw in clock wise until itjust touches the throttle lever then con tinue turning2 full turns Final Carburetor Adjustment Make final adjustments to the carburetor when the unit is fully reassembled Refer to Carburetor Adjustment in Part I General In...

Page 60: ...two 2 screws and retainers from the starter housing 2 Wind one or more extra turns of rope onto the pulley 3 Replacetheretainersandscrews NOTE Torque the retainer screwto 20 30 in lb 2 3 3 4N m after additional rope is wound onto the pulley 4 Pull the rope out to its full length and let it return until the pull handle rests against the starter housing NOTE Do not add any more tension thanis necess...

Page 61: ...screws and retainers 3 Remove the starter pulley from the starter housing 4 If necessary remove the starter spring from the starter housing NOTE To prevent injury when removing the starter spring drop the spring into a trash container which will release the spring from the housing NOTE Once the starter springis removed from the starter housing a service replacement spring prewound and containedin ...

Page 62: ...y thatis in contact with the starter spring 3 Make sure old grease and dirt are cleaned from all starter components before reassembling 4 12 NOTE Two types of starter pulleys were used in the production of the AC 1 engine Your unit is equipped withone of the starter pulleys shown Starter Inspection and Service 1 Inspect the starter rope for wear or frays E Replace the rope if necessary ...

Page 63: ...rs and carefully re move the spring retainer c Placethespringintothestarter housing Make sure the spring hook is installed into the groove of the starter housing d Make sure the spring windings are laying flat against the starter housing around the entire circumferenceof the spring Hold the spring in this position and carefully release the needle nose pliers holding the spring 2 Insert the rope th...

Page 64: ...ound onto the pulley 5 6 7 Apply a small amount of grease Mobilgrease R HP or equivalent to the post in the starter housing spring and the backside of the pulley Install the rope guide eyelet onto the starter rope Place the rope through the eyelet Install the pull handle on the rope and secure it with a single knot 2 6047 089 2 6060 156 4 14 2 6065 157 ...

Page 65: ...all thetwo 2 pulley retainers and screws Torque the screws to 20 30 in lb 2 3 3 4 N m I 11 Pull the rope out to itsfull length and let it return Check the spring tension and adjust as necessary Referto Adding Starter Spring Tension on page 4 10 for the location of the starter rope 2 6047 086 Breather Hose Plug Breather Hose BREATHER DISASSEMBLY AND REASSEMBLY 1 Remove the breather hose assembly fr...

Page 66: ...g plug into the hose 2 Slide the breather hose assembly from the inside out into the rocker arm cover until the breather hose seats into the cover 2 6060 159 1 Remove the spark arrester screw and cover 2 Push the spark arrester screen out of the cover 3 Inspectthesparkarresterscreen If the screenis clean reinstall the screen cover and screw If the screenis plugged clean or replace 4 16 SPARK ARRES...

Page 67: ...ecting rod from the piston Piston Inspection and Repair 1 Inspect the piston and piston rings for wear and damage Referto the specifications and tolerances in Part 1 General Information Replace the piston and piston rings if necessary 2 Inspect the ring grooves on the piston for carbon deposits Clean the ring grooves thoroughly with an old broken ring 4 17 ...

Page 68: ... Check the bearing area lower end for excessive wear score marks running and side clearances Refer to the specifications and tolerances in Part 1 General Information Replace the connecting rodif necessary Reassembly 1 Install the piston rings into the ring grooves in the piston 2 6047 100 RING PLACEMENT TOP Compression Ring Scraper ring BOTTOM Oil Control Ring MIDDLE Compression ...

Page 69: ...ttons are installed with the recess of the button facing the piston CYLINDER HEAD INSPECTION REPAIR Cylinder Inspection and Repair 1 Check all gasket surfacesto make sure they are free of debris Gasket surfaces must also be free of deep scratches or nicks 2 Inspect the cylinder and cylinder head for wear and damage 3 Inspect the intake port of the cylinder head for blockage Clean if necessary 4 In...

Page 70: ... Although these symptoms could also be attrib uted to worn rings remove and check the valves first 3 Check the valve guides for excessive wear If a valve guide is worn beyond specifications it will not guide the valve in a straight line This may resultin burnt valve faces or seats loss of compression and excessive oil consumption Replace cylinder head if necessary 2 6047 118 CRANKCASE INSPECTION R...

Page 71: ...e parts if necessary 3 Inspect the teeth on the cam gear Ifthe teeth are badly worn chipped or missing replace the cam gear Cam Bracket Reassembly 1 Make sure you haveall of the necessary partsto reassemble the cam bracket assembly 2 Install the cam followers to the cam bracket NOTE Make sure the cam followers are installed to the end of the bracket with the step on it 3 Install the cam gear to th...

Page 72: ...visible signs of damage Replace the capif necessary Clutch Inspection 1 Check the clutch rotor for wear or damage Replace if necessary 2 8080 162 Muffler Inspection and Cleaning The muffler should be removed periodically to inspect for excessive carbon build up Excessive deposits around the exhaust port will cause poor engine performance If carbon build up cannot be cleaned replace the muffler Ins...

Page 73: ...er Pawl Repair Kit has been installed holes in bottom of the flywheel below pawl pins Engine Other signs of fatigue wear or damage to the flywheel Starter Pawl Repair Kit P N 180142 is available to repair the flywheel This kit contains 2 pawl pins oversized two 2 pawl springs and two 2 pawls To install the kit an arbor press 0 228 inch 5 79 mm drill and drill press are required Installa tion instr...

Page 74: ...General Information Troubleshooting Disassembly Inspectionand Repair Reassembly ...

Page 75: ...tall Spark Plug 5 12 Install Muffler 5 12 Install Intake Baffle 5 13 Install Carburetor Mount Insulator 5 13 Install Ignition Module 5 14 i Install Fan Housing 5 15 Install FuelTank And FuelTank Bracket 5 15 Install Starter ModuleAssembly 5 15 Install Clutch 5 16 Install Primer Bulb CarburetorAnd Connect Fuel Line 5 17 InstallAir Filter Base AirFilter and Air Filter Cover 5 18 Assemble Handle 5 20...

Page 76: ...new gaskets Typical assembly sequence 1 Install Seal 2 Install Cam Bracket Assembly 3 Install Piston Connecting Rod 4 Install Cylinder 5 Install Oil Pan 6 Cylinder Head Assembly 7 Install Rocker Arm Assembly 8 Rocker Arm to Valve Clearance 9 Install Spark Plug 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Install Muffler1 Install Intake Baffle Install Carburetor Mount Insulator Install Flywheel Ins...

Page 77: ...e installation of the seal easier grease the inner ring of the seal with Mobilgrease R HP or an equivalent InstallCam Bracket Assembly 1 Rotate the crankshaft until the crankpinis at top 5 dead center between the timing marks 2 Slide the cam bracket assembly into the crankcase with the open hole of the cam gear down 6 o clock and the blocked hole at the top 12 o clock 5 4 I 2 6047 109 2 6047 109 2...

Page 78: ...is parallel to the crankcase without turning the engine 3 Install thecam bracket assembly into the crankcase with the two 2 screws Torque the screws to 15 20 in lb 1 7 2 2 N m Install Piston connectingRod 1 Make sure the piston rings are installed correctly as shown I 2 6047 112 5 5 ...

Page 79: ...se with the lettering on the bearing of the connecting rod facing the crankshaft counterweight Slideit down in the crankcase Angle it slightly and roll it into place Be sure not to dislodge the wrist pin buttons 2 6047 113 InstallCylinder 1 Install the cylinder to crankcase gasket Always use a new gasket While holding the piston con necting rod in place slide the cylinder into the crankcase NOTE H...

Page 80: ... Install the the cylinder with thetwo 2 screws into the crankcase Do not tighten 3 Place two 2 newO ringsonthecylinder Oil them lightly Install Oil Pan 1 Install thesix 6 screwsintotheoilpan Torque the screws to35 45 in lb 3 9 5 0 N m ...

Page 81: ...er head which include two 2 valves valve springs and retainers NOTE Always match intake and exhaust parts when assembling the cylinder head 2 Install the valves and valve springs 3 Install thetwo 2 valve spring retainers Make sure the retainers lock onto the valve stems properly 5 8 1 I 2 6047 118 2 6047 119 ...

Page 82: ...n the gasket goes to the spark plug side of the cylinder and the dome side of the gasket should be up 5 Place the cylinder head over the four 4 studs 6 Sealthe two 2 cylinder studsintherocker box with RTV sealing 7 Install the push rod guides over the cylinder studs 5 9 ...

Page 83: ... to Cam Bracket Disassembly and Reassembly in Part 4 inspection and Repair Torque the cylinder head hex nuts to 35 40 in lb 3 9 4 5 N m Torque the nutsin an X pattern Torque thetwo 2 cylinder screws to 35 40 in lb 3 9 4 5 N m Install Rocker Arm Assembly 1 Install the rocker arm adjusting nuts rocker arm pivots and rocker arms NOTE Always match intake and exhaust parts when assembling the rocker ar...

Page 84: ...ocker arm to valve clearance for both the intake and exhaust is 003 006 in 076 mm 152 mm 3 If the clearance is not within specification adjust as follows a Turntheadjustingnut usinga 5 16 in 8 mm wrench or nut driver To increase the rocker arm to valve clearance turn the adjusting nut counterclockwise To decrease the rocker arm to valve 5 clearance turn the adjusting nut clockwise b Recheck the cl...

Page 85: ...lace the muffler baffle in place 2 Install the muffler with the three 3 mounting bolts Install the lower bolt first to ease the installationof the toptwo 2 bolts NOTE The 5 mm nut must be held in the slot next to the spark plug before installing the top rear muf fler bolt NOTE Be careful not to crossthread the muffler mount ing bolts Torque the muffler mounting bolts to 40 45 in lb 4 5 5 0 N m 5 1...

Page 86: ...2 hex nuts on the back of the carburetor mount insulator For Units with Engine Serial Number 405000001 and Greater The two 2 hex nuts areretainedinthecarburetormountinsulator 2 Install a new gasket to the back of the carburetor mount insulator Install the carburetor mount insulator to the crankcase with the two 2 screws Torque the screws to 30 35in lb 3 3 3 9 N m 5 13 ...

Page 87: ...lutch rotor to hold the flywheelin place Install Ignition Module 1 Install the ignition module ground lead tab terminal and module fastening screws 2 Move the ignition module away from the flywheel as far as possible Tighten the fastening screws slightly J I27 2 6047 128 3 4 5 Insert a0 008 0 012 in 0 201 0 305 mm feeler gauge or shim stock between the ignition mod ule and the flywheel magnet surf...

Page 88: ...d to the fuel tank 2 Install the fuel tank and fuel tank bracket with the two 2 screws Torque the screws to 25 35 in lb 2 8 3 3 N m Install Starter Module Assembly 1 Place the starter module over the crankshaft 2 Install the starter rope eyelet bracket with the two 2 screws Torque the screws to 15 20 in lb 2 0 2 5 N m NOTE It may be necessary to pull the starter rope slightly to enable the starter...

Page 89: ...ENGINE ASSEMBLY cont Install Clutch 1 Install the washer and clutch rotor to the crankshaft Make sure the spacer is installed on the crankshaft 3 Install the isolator onto the starter housing 5 16 ...

Page 90: ...Bulb Carburetor And connecty ci Fuel Line Use the following procedure to install the primer bulb carburetor and fuel lines into the air filter base 1 Install the primer bulb into the air filter base Escrews he N m t 2 Installtwo new carburetor gaskets and the carburetor into the air filter base The larger gasket goes on the air filter base side and small one on the carburetor to isolator side the ...

Page 91: ... line for excess fuel flow during the primer operation The short fitting on the bulb comes from the carburetorand the long fitting goes to the fuel tank InstallAir Filter Base Alr Filter and Air Filter Cover 1 Install the Z bendof the throttle cable into the third hole from the top in the carburetor throttle lever 5 18 2 6047 139 Short Fitting To Carburetor Long Fitting To Tank 3 6047 140 2 6047 1...

Page 92: ...etor to the carburetor mount insulator with the three 3 screws The breather hose must be mounted to the air filter base at the same time Torque the screws to 30 35in lb 3 3 3 8 3 Install the air filter element onto the air filter base 4 Install the air filter cover with the three 3 N m screws Torque the screws to 25 30in lb 2 8 3 3 N m 5 19 ...

Page 93: ...to the grooves in the bottomof the lower handle Place the switch wire in the bottom of the slot and then the throttle cable NOTE Make sure the wires are placed to the rear of the switch This will ensure that the switch is in the correct on off position 2 Install the spring into the trigger 5 20 Lead 20647 143 Spring ...

Page 94: ... the and throttle trigger assembly inthe lower Torque the retainer screw to 15 20 in lb N m Install Upper Handle 1 Install the upper boom into the handle witch handle 1 NOTE For units that take attachments make sure the spring is installed in the clutch hous ing drum assembly before installing the upper boom I 2 Locate the anti rotation cap screw and place the boom onto the cap screw Torque the sc...

Page 95: ...ll hold the boom onto the anti rotation cap screw L 5 Install the upper handle with the six 6 screws To aid in the installationof the upper handle lu bricate the isolator with soap and water 6 Torque the screws to 20 25 in lb 2 2 2 8 N m Cut the tape and remove it from the lower handle 5 22 ...

Page 96: ...ne cover screw to 20 25 in lb 2 5 3 0 N m Before placing the unit back into service be sure to do the following 1 Make sure all of the fasteners are tightened securely 2 Fill the fuel tank with fresh gasoline and check the oil level in the oil pan Refer to Oil and Fuel Recommendations in Part 7 General Information speed mixture and idle speed settings Refer to Carburetor Adjustment in Part 7 Gener...

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Toro AC-1, Service Manual

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