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TC/TM SERIES 2-Cycle Engines

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1. EE 28 ae 28 iud cU uL M Lu A 28 SERVIGE 28 DISASSEMBEY PROCEDURE 2 a Este uuu i tese 28 ASSEMBLY PROCEDURE eee LM eee 29 Tecumseh Power Company 2005 GENERAL INFORMATION za ee seele 30 OPERATION net a eis ee tea ee eee 30 COMPONENTS ee ee ee ee nee eee eee 30 IGNITION TROUBLESHOOTING 2 teens 31 ee ne ee TET 32 SERVICE aan 32 agri E ee ee a ee I T 32 SPARK PLUG SEBRVIGOE ill 32 CHAPTER 7 INTERNAL ENGINE AND CYLINDER 33 GENEBAL INFORMATION 33 OPERATION m 33 MANUAL COMPRESSION RELEASE piro nl 33 COMPONENTS DN HERES 34 EROUBEESEOOTINGO ur ae ee 35 36 TESTING 37 ENGINE KNOCK S an ea tad a ey 37 E NGINE OVE RFEA T S ee Bee cM et EN edu 37 SURGES OF RUNSUNEVENEF a ee 37 ENGINE MIS RIRE ee ae
2. Fuel Tank Air Cleaner Housing Poly Air Cleaner Flocked Screen Air Cleaner Cover Cover Screw CHAPTER 3 CARBURETORS AND FUEL SYSTEMS GENERAL INFORMATION TC TM engines almost exclusively use diaphragm type carburetors to be able to run effectively at any operating angle The diaphragm carburetors are produced by Tecumseh Walbro and Tillotson for Tecumseh The carburetors use an internal diaphragm fuel pump to supply the fuel to the carburetor fuel metering chamber The metering diaphragm has one side exposed to intake manifold pressure and one side exposed to atmospheric pressure This diaphragm provides the same basic function maintaining the proper fuel level in the carburetor as the float A limited number of TC engines were produced as outboards using a Tecumseh Series II float style carburetor Consult the Two Cycle Technician s Handbook part 692508 if service is required on this series of carburetor When servicing carburetors use the engine model and specification number to obtain the correct carburetor part number alternate method to find the correct carburetor part number is to use the manufacturing number and date code stamped on the carburetor and convert this number to a part number In the carburetor section of the Master Parts Manual Microfiche Catalog or Electronic Parts Catalog a cross reference chart will convert a carburetor manufacturing number to a Tecumseh part number When using computer
3. ENGINE MISFIRES 1 2 3 Check the spark plug for a fouled condition Replace if questionable Check the carburetor for the proper adjustments See Pre sets and Adjustments See Chapter 3 under Service Check the air gap dimension Follow the procedure in Chapter 6 under Service Use an in line spark tester to see if the problem is ignition related 37 4 Check the flywheel key for partial shearing 5 Remove the muffler to check for excessive carbon build up in the combustion chamber or exhaust port 6 Inspect the intake gaskets crankcase seals or gaskets for a leaking condition Use a commercially available crankcase pressure tester and follow the tester s recommended test procedure See Disassembly Procedure in this chapter for component removal ENGINE VIBRATES EXCESSIVELY 1 Remove the engine drive and check the attached equipment for an out of balance condition 2 Check the engine mounting bolts make sure they are tight 3 Check the engine crankshaft on the P T O end using a straight edge square or dial indicator Blades or adapters must be removed Any deflection will cause a vibration problem 4 Check the internal engine for bearing roughness or wear crankshaft bearing journal wear or a worn cylinder or piston LACKS POWER OR WILL NOT START 1 Check the air intake for an obstruction dirty filter saturated filter or other debris 2 Check the exhaust for a restriction preventing proper exhaust flow
4. 19 mm deep well socket Drain the fuel from the tank by sliding the fuel line clamp off the fuel tank fitting twist and pull the fuel line off and drain the fuel into an approved container outdoors and away from any open flame or combustion source Be sure engine is cool To avoid death or serious injury DO NOT pour fuel from engine or siphon fuel by mouth 4 Remove the two screws on the filter cover the filter element s and then the two hex nuts and spacers if equipped on the carburetor studs diag 7 23 Remove the self locking nut and washer on the blower housing stud and remove the fuel tank All TC300 Type II non rotary 0125 317 mower use 030 762 mm part number 670297 Air gap part number 670321 All TC200 TC300 Type II rotary mowers and all TM 7 22 Fuel Tank Air Cleaner Housing Poly Air Cleaner Flocked Screen Air Cleaner Cover Cover Screw N 43 6 Remove the rewind starter assembly by removing three machine screws diag 7 24 7 Remove the ignition grounding lead off the ignition module and remove the ignition module using a 1 4 socket or Torx T15 drive 8 Use the strap wrench part 670305 to hold the flywheel and loosen the flywheel nut until it is flush with the end of the crankshaft 9 Use flywheel puller part 670299 to pop the flywheel off the crankshaft taper unthread and remove the pull
5. TELUMSEH TECHNICIAN S HANDBOOK TC TM SERIES 2 Cycle Engines N TECUMSEH IMPORTANT NOTICE This handbook covers repairs and adjustments not covered within the Operator s Manual and it is intended for individuals who have a general understanding of internal combustion engines adequate training experience and who practice proper tool usage Service procedures should be clearly understood and practiced when servicing Tecumseh Engines Safety Definitions Statements in this manual preceded by the following words and graphics are of special significance Or WARNING WARNING indicates a potentially hazardous situation which if not avoided could result in death or serious injury NOTE Refers to important information and is placed in italic type It is recommended that you take special notice of all items discussed on pages 1 and 2 and wear the appropriate safety equipment Notice Regarding Emissions NOTE Engines which are certified to comply with California and U S EPA emission regulations for SORE Small Off Road Equipment are certified to operate on regular unleaded gasoline and may include the following emission control systems EM Engine Modification and TWC Three way Catalyst if so equipped Tecumseh Contact Information Contact your nearest Authorized Tecumseh Servicing Dealer if You are unable to perform service procedures covered in this handbook You have questions abo
6. 3 Check the fuel oil mixture for the gasoline being fresh and the proper amount and kind of oil used Replace if questionable 4 Visually check the operation of the throttle air vane governor and choke if applicable for restrictions preventing proper movement 5 Check the carburetor for the correct idle mixture adjustment Clean the carburetor if the problem persists See Chapter 3 under Service 6 Inspect the intake gaskets crankcase seals or gaskets for a leaking condition Use a commercially available crankcase pressure tester and follow the tester s recommended test procedure See Disassembly Procedure in this chapter for component removal 7 Inspect the engine cylinder and ring s for a worn condition 8 Check the flywheel key for partial shearing 9 Check that the compression release moves outward to the closed position as soon as engine starts SERVICE GENERAL INFORMATION TC TM engines do not have oversized pistons available If the engine bore diameter exceeds the maximum engine specification and new installed rings exceed the maximum ring end gap a new short block or engine will be necessary Engines built with needle bearing P T O main bearings have been upgraded to be serviced with P T O ball bearing replacements Gaskets have replaced Loctite sealant between the engine cylinder and the crankcase Crankcases that used Loctite sealant between the cylinder cover and the engine crankcase have been upgraded to use
7. ENGINE SPECIFICATIONS AND SEARS CRAFTSMAN CROSS REFERENCE TORQUE SPECIFICATIONS The torque specifications listed in this chart are to be used for replacing components after disassembly not for checking an existing engine bolt torque Checking a torque value on a new or used engine may be lower due to torque relaxation that occurs on all engines from thermal expansion and contraction However sufficient clamping force exists and a re torque is not necessary Crankcase Cover to Crankcase 88 0 TC Type I II Cylinder Block to Crankcase 88 0 TC Type I II 1 meermenwes ECT OT wo _ wo me me 0 ww Speed Control to Base 35 0 3 0 4 0 TC Type Carburetor to Block Nut 35 0 TC Type Il and some TM morrem Compression Release TM 100 0 Er NE 11 0 48 ENGINE SPECIFICATIONS All Dimensions are in inches TC200 TC300 Type Il HP Approx 1 Kw 1 Kw 1 Kw Bore EK 4370 EN 49 7495 43 7495 E 43 1 4380 36 52 1 7505 44 46 1 7505 44 46 Stroke 1 EE 7 1 125 7 1 4 ar 7 Spark Plug Gap Ignition Mod 0125 030 0125 ule Air Gap Note A Piston Ring 004 101 005 127 005 127 End Gap 014 355 015 381 015 381 Sa Diame 1 4330 36 398 1 7450 44 303 1 E 44 E B 1 4345 36 436 1 7465 44 361 1 E 44 E B Piston Ring 0485 1 231 0485 1 2319
8. diag 1 2 Using model TC200 2015B 2354D as an example inter pretation is as follows See Table 1 1 1 2 3 TC200 2015B 1 Engine Model Number 2 Specification Number 3 D O M Date of Manufacture Sample TC200 Decal ll TC300 Models A sample TC300 decal is pictured for reference See diag 1 3 Using model TC300 3133C B 5114G as an example interpretation is as follows See Table 1 2 TC300 3133C 5114G SN Engine Model Number Specification Number Warranty Category D O M Date of Manufacture Sample TC300 Decal Table 1 1 TC200 Engine Model Code Designations Code ModelNumber Number ie Tecumseh Engine Ss turer Indicates compact model 20 Indicates 2 0 cubic inch displacement Specification Number 2015B Indicates number used for identifying the parts ofthe engine Serial D O M Designation 2 Is the last digit in the year of manufacture 1992 354 Indicates the calendar day of that year 354th day or December 20 Indicates the plant line and shift on which the engine was built at the factory Table 1 2 TC300 Engine Model Code Designations Model Number Indicates Tecumseh Engine Manufac turer Indicates compact model Indicates 3 0 cubic inch displacement Specification Number 3133C Indicates number used for identifying the parts of the engine Warranty Code Indicates Warranty Information See current Operator s Manual for information
9. disengaged position The brake spring slows the pulley and pawl from turning diag 5 1 TYPE This starter uses two engagement pawls bolted to the flywheel with shoulder bolts Each pawl uses an engagement spring to keep the pawl in contact with the pulley hub The pawls lock into two of the four notched surfaces located on the starter pulley when the starter rope is pulled When the engine fires and the flywheel speed exceeds the speed of the starter pulley the pawls disengage and centrifugal force keeps the pawls in the disengaged position diag 5 1 COMPONENTS 1 Blower Housing 4 Pulley 8 Retainer Screw 2 Recoil Spring 5 Pawl 9 Dog Screw 3 Washer 6 Brake Spring 10 Starter Dog 7 Retainer 11 Pawl Spring TC Typel TC Type gis SERVICE Starter related problems will require the starter to be removed from the engine to diagnose the cause On TC Type engines try starter operation off the engine to see pawl engagement Visually inspect the starter pawl brake spring retainer pulley washer s and rope for wear or breakage Repair or replace as necessary On 11 TM engines recoil disassembly is necessary only if the pulley is worn the recoil will not retract or the rope needs replacement Check starter pawl engagement on the flywheel for broken springs sticking or bent condition or loose pawl screws DISASSEMBLY PROCEDURE 1 Rem
10. procedures for TM engines 44 iger A TSJA rie jit Torx Head Bolt OTE I ASSEMBLY TM 1 Remove old gasket material Be careful not to damage scratch or burr the sealing surfaces Clean the crankcase cylinder piston assembly crankshaft and crankcase cover using cleaning solvent and blow dry with compressed air Install the crankcase flywheel end oil seal using seal protector part 670301 on the seal The oil lip spring side of the seal must face toward the crankshaft bearing Press until the oil seal touches the bearing Install crankcase PTO end oil seal using seal protector installer part 670275 to protect the seal during installation The oil lip spring side of the seal must face toward the crankshaft bearing Press until the oil seal touches the bearing NOTE Lube piston skirt and cylinder bore with clean two cycle oil prior to piston installation 4 Place ring compressor part 670391 in the cylinder with the outer taper centered in the cylinder and the opening in ring compressor facing the PTO end Make sure the ring end gaps are staggered and away from the opening in the ring compressor Use ring compressor to compress the piston rings and push the piston into the cylinder while aligning the center line of the crankshaft with crankcase diag 7 28 Rotate the ring compressor to align the opening with the connecting rod and remove the ri
11. starts to decrease Note this position and turn the mixture screw back clockwise halfway between the two engine R P M drop off positions Verify the engine will accelerate from low speed to high speed and that the idle speed remains at the desired setting Once adjustments are complete center the adjustment limiter cap between the two stops and press inward to engage the limiter The limiter will snap into position and engage the adjusting screw All future adjustments should now be made using the adjusting slot in the limiter cap Once the limiter cap is snapped into place it is not possible to remove the limiter or to adjust the mixture screw beyond the limits of the limiter assembly Make sure that initial adjustments are made per the above procedure prior to engaging the limiter cap TC TM EMISSIONIZED TECUMSEH CARBURETOR The Tecumseh emissions diaphragm carburetor has fixed main and idle jets diag 3 18 It uses a married idle and high speed circuitry The idle has a metering jet that can be removed for cleaning It is covered by a small cap that must be removed to expose the jet for servicing No adjustments or presets are required The idle jet should be turned until tight 5 8 inch pounds 0 5 Nm and the cap should then be installed to cover the jet 0 M 0 ES eure 0 23 FUEL TANK SERVICE TC Type engines have fuel tanks with an integral fuel screen and integral outlet fuel fitting Integral
12. 0125 317 mm gauge part 670297 for all 200 Type engines TC300 Type 1 rotary mower engines and all TM All other TC300 Type Il applications require a 030 762 mm air gap dimension use gauge part 670321 Torque the module mounting screws to 30 40 inch pounds 3 3 Nm 4 5 Nm Remove the air gap gauge rotate the flywheel to assure it does not strike the ignition module Attach ignition grounding lead to the module terminal diag 7 22 NOTE When using 030 762 mm air gap gauge it is critical to push the module against the flywheel magnet before tightening the mounting screw 18 19 20 21 Install the blower housing and rewind assembly Replace the debris guard if applicable Connect the fuel line at the carburetor position the fuel line clamp on the fuel fitting and attach the fuel tank to the engine using the mounting spring On TC Type Il engines hook the upper fuel tank mounting tab over the blower housing stud and the carburetor studs Make sure the O ring is in position between the fuel tank and the carburetor Tighten the retaining nuts install filter s and attach the air cleaner cover Reset the governor and or speed control using the procedure in Chapter 4 under Service Install the spark plug and connect the high tension lead DISASSEMBLY PROCEDURE TM 1 Remove the high tension lead boot from the spark plug by twisting and pulling Remove the spark plug using a 3 4
13. 0485 1 2319 Groove Width 0495 1 257 0495 1 2573 0495 1 2573 Top Bottom Piston Ring 046 1 168 046 1 1684 046 1 1684 Width 047 1 193 047 1 1938 047 1 1938 Crankpin Jour 15 201 15 201 nal 15 214 15 214 Diameter Main Bearing 15 869 15 869 Diameter 15 882 15 882 P T O Side Main Bearing 4993 12 682 4993 12 682 Diameter 5003 12 702 5003 12 707 Flywheel Crankshaft 1016 1016 N A N A 305 305 End Play Note A TC300 rotary mower applications use 0125 317 mm air gap Note B Mechanically retained needle bearings use 6850 6855 17 399 mm 17 411 mm or 6870 6875 17 449 mm 17 462 mm Note C Check to determine bearing diameters 7498 7503 19 044 mm 19 057 mm 6695 6699 17 005 mm 17 015 5898 5903 14 980 mm 14 993 Note D Engine with P T O ball bearings no end play 49 SEARS CRAFTSMAN CROSS REFERENCE 143 042070 049 3604A or 3604B 143 042072 049 3621B 143 681001 TC300 3010A 143 681021 TC300 3013A 143 941600 200 2103C 143 961670 TC200 2124D 143 961672 200 21030 143 971670 200 2103E 143 971674 200 2124 143 972070 TC300 3153E 143 982070 TC300 3176F 143 982072 TC300 3173F 143 992070 TC300 3187F 200 651001 TC200 2019C 200 681001 TC300 3010A 200 681021 TC300 3013A 200 681061 TC300 3021A 200 691001 TC300 3019A 200 691011 TC200 2040D 200 701011 TC200 2045E 200 701021 TC300 3027B 200 701031 TC300 3013B 200 70
14. 4 6 31 mm hook on one end to pull the muffler spring off diag 7 9 A diagram of the wire hook is in the tool section of this manual On TC Type Il engines remove the shoulder bolts holding the muffler on 14 Note or mark the location of the cylinder to the crankcase and remove the four Torx bolts holding the cylinder to the crankcase using a six inch long Torx T30 driver part 670320 Pull the cylinder off squarely using caution so the rod does not bend Use a 3 8 open end wrench to loosen the four cylinder nuts on early production type engines diag 7 10 15 Insert seal protector part 670301 to protect the flywheel end oil seal and seal protector part 670303 for the P T O end oil seal diag 7 10 16 Remove the crankcase cover screws and remove the cover On TC Type II engines with a ball bearing in the cover the cover and crankshaft will be removed as an assembly 17 Turn the crankshaft to the 90 past the top dead center T D C position and remove the crankshaft out of the crankcase opening while sliding the connecting rod off the crankpin and crankshaft TC Type Il engines use a pressed in mechanically retained needle bearing in the connecting rod Older TC engines use loose crankpin needle bearings make sure to collect all 23 needle bearings Engines built after Aug 1995 may also use loose needle bearings grease retained 36 needles are required diag 7 11 18 Use a bearing splitter and an
15. CAUTION Do not use a sand blaster to clean spark plugs Microscopic particles left in the plug can score the engine cylinder during operation Use solvent and a wire brush to clean the plug and compressed air to blow out completely Consult your Master Parts Catalog for the correct spark plug and replace if necessary Set the spark plug gap at 030 762 mm diag 6 4 Install the spark plug in the engine and tighten to 230 inch pounds 2 6 Nm torque If a torque wrench is not available screw the spark plug in as far as possible by hand and use a spark plug wrench to turn the spark plug 1 8 to 1 4 of a turn more if using the old plug and a 1 2 of a turn more if using a new spark plug NOTE When using the 670321 gauge push the module tight to the flywheel before tightening 32 All TC300 Type II non rotary 0125 317 mm i mower use 030 762 mm part number 670297 Air gap part number 670321 All TC200 TC300 Type Il rotary mowers and all TM 6 3 CHAPTER 7 INTERNAL ENGINE AND CYLINDER GENERAL INFORMATION TC TM series engines use two cycle operation Two cycle engines provide a higher horsepower to weight ratio than the same size four cycle engines Two cycle engines use two piston strok
16. Code Serial D O M Serial D O M Designation EM the last digit in the year Se NN manufacture 1995 Indicates the calendar day of that year 114th day or April 24 G Indicates the plant line and shift on which the engine was built at the factory TM Models A sample TM decal is pictured for reference See diag 1 4 Using model TM049XA 3617B A 4056CA as an exam ple interpretation is as follows See Table 1 3 TMO49XA 36178 4086 fp LE Engine Model Number Specification Number Warranty Category D O M Date of Manufacture Sample TM Decal Short Blocks New short blocks are identified by a tag marked SBH Short Block Horizontal or SBV Short Block Vertical Original model identification numbers of an engine should always be transferred to a new short block for correct parts identification See diag 1 5 OIL REQUIREMENTS Table 1 3 TM Engine Model Code Designations Model Number M Indicates multi position model identifying the parts of the engine A Indicates Warranty Information See cur EN uu Serial D O M Designation 4056CA Is the serial number or D O M Date of Manufacture Is the last digit in the year of manufacture 2004 Indicates the plant line and shift on which the engine was built at the factory 056 Indicates the calendar day of that year 56th day or February 25 A Indicates the location of where the engine was built at the factory SBV OR
17. NOTE The sleeve spacers must be installed before installing the fuel tank on later TM engines TC TYPE Il EARLY TM Through Hole Toward Spark Plug Through Hole Away From Spark Plug Insulator Spacer Vacuum Channel Vacuum Channel Toward Cylinder Toward Carburetor Insulator Spacer LATER TM Sleeve Spacers 0 9 Vacuum Channel Toward Carburetor u N AN ai Through Hole Away From Spark Plug N Insulator Spacer 3 16 22 EMISSIONIZED TC TILLOTSON CARBURETOR The Tillotson carburetor is an emissions grade carb It has a married idle and high speed circuitry with limited jet adjustments on the idle diag 3 17 EMISSIONS CARBURETOR IDLE MIXTURE ADJUSTMENT PROCEDURES The carburetor is preset at the factory at a normal setting required for initial engine operation Allow the engine to reach normal operating temperature after 3 5 minutes Set the engine speed control in the idle position With the engine at idle speed Note must be less than 2400 R P M for accurate adjustment Using a small tip screw driver that fits through the access hole in the limiter cap adjust the mixture screw slowly clockwise until the engine R P M just starts to decrease Stop and note this screw position Turn the idle mixture screw slowly counterclockwise As the engine increases R P M continue to slowly turn the screw counterclockwise until the engine R P M
18. arbor press to remove the ball bearing and cover assembly from the crankshaft on TC Type II if necessary 19 Remove the oil seals by supporting the area around the seal and using a small punch or screwdriver to drive out the seal BEARING AND SEAL SERVICE TC TYPE AND TC TYPE Il The crankcase and crankcase cover oil seals can be removed by prying out or tapping out with a screwdriver On older TC engines a retainer ring must be removed with a pick before the crankcase bearing can be pressed out diag 7 12 Remove the needle bearing by using the bearing installer tool part 670302 inserted from the outside to drive the bearing out To install a new bearing in the engine crankcase place a new caged needle bearing on the installation tool part 670302 Use bearing installation tool part 670304A for installing the crankcase cover caged needle bearing Place the printed side of the bearing toward the installation tool Lightly oil the outside of the bearing and the crankcase bearing bore Press the bearing into the crankcase until the tool is flush with the crankcase or cover housing Insert the retainer ring if applicable diag 7 13 Install a new crankcase oil seal using seal protector installer part 670301 Install the crankcase cover oil seal using seal installer part 670303 The metal case of the seal goes onto the seal protector first Lightly oil the outside of the seal Press the tool and seal in until
19. ee er ee 37 ENGINE VIBRATES EXGESSIVELT einen ek 38 LACKS POWER OR WILL NOT STAR Tr ee ae 38 SERVICE nee r a 38 GENERALINFORMATION TE 38 DISASSEMBLY PROCEDURE TC 1 AND TC TYPE 38 40 BEARING AND SEAL SERVICE TC 40 ASSEMBEY TYPEILANDTETYPE lea Me toad 41 43 DISAS SEMBE ly 43 44 BEARING AND SEAL SERVICE STM sri E ae ec 44 NN E rrt 45 47 CHAPTER 8 ENGINE SPECIFICATION AND SEARS CRAFTSMAN CROSS REFERENCE 48 MORQUE SPECIFICATION S ota RD etsi d Dd Dei 48 ENGINE SPECIFICA masse 49 SEARS CRAFTSMAN CROSS REFERENCE snieni aa 50 CHAPTER 9 EDUCATIONAL MATERIALS AND TOOLS 51 54 CHAPTER 1 GENERAL INFORMATION General Safety Precautions WARNING Read the original equipment manufacturer s manual s and this handbook thoroughly before servicing Tecumseh engines Always follow recommended service procedures ouch procedures affect the safe operation of the equipment and the safety of you and or the operator Failure to follow the instructions and warnings may result in serious injury or death Call Tecumseh Power Company at 1 800 558 5402 or visit www Tecumseh Power com if you have any questions A Use
20. engine s governed speed COMPONENTS AIR VANE BACKLASH SPRING GOVERNOR LINK GOVERNOR SPRING MOUNTING SCREW SPEED ADJUSTMENT SCREW SPEED CONTROL BODY SPEED CONTROL LEVER SPEED CONTROL PLUNGER Qr spore oo Tes TC TYPE Spring Hooked In Notch Air Vane TYPE Air Vane TC TYPE and EARLY TYPE Insert Throttle Link 4 2 25 TROUBLESHOOTING ENGINE OVERSPEEDING 1 If the engine runs wide open faster than normal shut the engine off or slow it down immediately 2 Visually inspect the air vane linkage carburetor throttle shaft and speed control for debris blockage binding breakage or incorrect hook up Check the governor spring for a stretched or distorted condition To view the components remove the recoil assembly and or fuel tank if necessary For information on the proper linkage or spring connections review the appropriate diagrams in this section 3 Clean correct or replace binding or damaged parts Set the speed control to the recommended engine R P M ENGINE SURGING 1 Try to stabilize the engine R P M by holding in one position the carburetor throttle shaft on the exterior of the carburetor 2 If the engine R P M stabilizes the governor or governor adjustment should be checked Follow the procedure under Governor Adjustment in this chapter If the engine R P M does not stabilize the engine will
21. main filter Extremely dirty operating conditions may require frequent filter cleaning or replacement OPERATION The outer cover holds the air filter element s and prevents debris from entering the filter box The air supply is filtered through the pre filter if equipped filter element polyurethane or paper and a flocked screen if equipped Pre filter elements do not extend the recommended air filter service intervals listed under Service However in extremely dirty operating conditions a pre filter element may increase the run time of the engine before the filter becomes restricted not to exceed the service recommendations and service on the filter is necessary TROUBLESHOOTING If the engine s performance is unsatisfactory needs Polyurethane Filter excessive adjustments starts smoking abnormally loses power the first component to be checked is the air cleaner A dirt restricted or an oil soaked filter element will cause noticeable performance problems A polyurethane element may be cleaned following the service procedure listed under Service in this chapter A paper type air filter should only be replaced Follow the procedure listed in the service section in this chapter for replacement Retry the engine after filter replacement or service If the problem persists after filter service additional solutions can be found in Chapter 7 under Troubleshooting SERVICE Cleaning and oiling the polyurethane element diag 2 1
22. part 670391 do not align the opening in the ring compressor with ring end gaps to compress the piston rings and push the cylinder onto the piston Remove ring compressor by sliding opening of tool past the connecting rod Do not rotate or twist the cylinder diag 7 18 Install Torx bolts and alternately torque the bolts to 80 95 inch pounds 9 04 Nm 10 7 Nm or on engines with studs instead of bolts push the cylinder down to a depth where the nuts can be started on the studs Finger tighten the nuts use a wrench to snug and torque the nuts to 70 100 inch pounds 7 9 Nm 11 3 Nm using a crowfoot on the torque wrench Install the exhaust gasket muffler spark arrestor if applicable bolts or muffler springs Torque the muffler bolts to 85 105 inch pounds 9 6 Nm 11 8 Nm of torque if applicable The longer ends of the springs hook into the bosses on the cylinder Use heavy gauge wire as shown in the tool section to stretch and hook the muffler springs diag 7 19 Install the muffler heat shield if applicable Remove the engine holder Attach the blower housing base using the three screws removed from the engine holder and torque the screws to 30 40 inch pounds 3 3 Nm 4 5 Nm Type models install the governor air vane assembly into the blower housing base as shown Some models use a spring clip to hold the air vane in position Insert and tighten the speed adjusting lever hold down screw to the blowe
23. parts look up system it is only necessary to enter this information in the search box using prefix OK for Tecumseh carburetors WA or WTA for Walbro carburetors or HU for Tillotson carburetors diag 3 1 OPERATION In the CHOKE or START position the choke shutter is closed and the only air entering the engine flows through Fuel openings around the choke shutter As the recoil Impulse assembly is operated to start the engine upward piston Intake Air travel creates a low pressure area in the crankcase High Engine Vacuum pressure atmospheric air rushes into the crankcase to fill the created low pressure area Since the majority of the air passage is blocked by the choke shutter a relatively small quantity of air enters the carburetor at increased speed The main nozzle and both idle fuel discharge ports are supplying fuel due to the low air pressure in the intake of the engine and the fuel side of the main diaphragm Atmospheric air pressure on the opposite side of the main diaphragm forces the diaphragm upward depressing the inlet control lever overcoming inlet spring pressure and allowing fuel to enter the fuel chamber through the inlet valve A maximum fuel flow through the carburetor orifices combined with the reduced quantity of air that passes through the carburetor make a very rich fuel mixture which is needed to start a cold engine diag 3 2 11 At IDLE the throttle shutter is almost closed the low press
24. proper adjustment and operation Check to see that the engine is properly secured to the equipment On rotary lawnmowers balance the blade and check the blade hub and crankshaft key for wear Replace as necessary Torque the bolts to the correct specification 6 Replace the spark plug with the correct replacement by using the Master Parts Manual Set the spark plug gap at 030 762 mm and install it in the engine Tighten the spark plug to 230 inch pounds 2 6 Nm of torque If a torque wrench isn t available screw the spark plug in as far as possible by hand Use a spark plug socket or wrench to turn the spark plug 1 8 to 1 4 turn further if using the old spark plug or 1 2 turn further if a new spark plug is used Reinstall the spark plug wire 7 Fill the fuel tank with the proper fuel oil mix 8 Start the engine and allow it run 3 5 minutes to reach operating temperature Adjust the carburetor if necessary see Chapter 3 under Service for the final idle mixture adjustment procedure and set the engine R P M s according to the specification number found on microfiche card 30 or computer parts lookup system STORAGE iF THE ENGINE IS TO BE UNUSED FOR 30 DAYS OR MORE Never store the engine with fuel in the fuel tank inside a building with potential sources of igni tion such as hot water or spacer heaters clothes dryers electric motors etc Gasoline can become unstable in less than 30 days and form deposits that can impede pr
25. require additional checks Some surging problems can be carburetor or fuel related Additional information can be found in the troubleshooting section of Chapter 3 If the problem persists after the governor adjustment check the engine R P M found on microfiche card 30 or in the computer parts lookup If the setting for high and low speed are within the listed specification and a slight surge is experienced increasing the engine idle speed slightly may eliminate this condition 4 Visually inspect the air vane linkage carburetor throttle shaft and speed control for debris blockage binding breakage or incorrect hook up Check the governor spring for a stretched or distorted condition To view the components remove the recoil assembly and or fuel tank if necessary For information on the proper linkage or spring connections review the appropriate diagrams in this section SERVICE For governor disassembly or assembly procedures see Service in Chapter 7 GOVERNOR ADJUSTMENT Three different styles of governor systems are used on TC TM engines Use the following illustrations diags 4 3 4 4 and 4 5 to identify the governor system used and the following procedure to adjust the governed engine speed TC TYPE Spring Hooked In Notch 1 Allow the engine to run for at least 5 minutes to reach the operating temperature Make sure the air filter 26 Using Vibratach if equipped is clean and the choke is in the of
26. screens or fittings are not serviceable diag 3 19 Some TC Type engine models use a pressed in fuel filter or a weighted filter and a flexible fuel line in the tank Pressed in fuel filters and fittings can be serviced using the following procedure diag 3 20 ile 24 Press the fuel fitting into the tank and feed the fuel line in until the filter can be removed through the filler neck Remove the filter and fuel line if necessary To install a new filter and fuel line Cut the end of the fuel line at approximately a 20 angle to make installation of the fuel line through the hole in the fuel tank easier Push the new fuel line through the tank outlet until the fuel line protrudes through the filler neck Cut the angled portion from the fuel line On tanks without weighted filters push a new filter on the fuel line For weighted filters slide the new retaining ring on the fuel line protruding from the filler neck Push the fitting into the line to the fitting shoulder Slide the retaining ring over the groove in the fitting and crimp the retaining ring using a pliers Attach the fuel line and weighted fuel filter if applicable Pull the fuel line through the tank outlet The filter barb or the fuel fitting barb must protrude from the tank B Lock Nut Washer c Fuel Tank Air Cleaner Housing Poly Air Cleaner Flocked Screen Air Cleaner Cover Cover Screw CHAPTER 4 GOVERNORS AND L
27. the crankshaft into the cylinder cover Place a drop of 680 Loctite in the crankshaft groove position supports under the cylinder cover and using an arbor press press the shaft into the bearing until it bottoms on the bearing Install the crankshaft and piston assembly into the crankcase at the same time Install a new bearing strip on the crankpin or grease retain the loose needles if applicable If the piston has an arrow on top the arrow must point toward the exhaust port side of the engine If the piston does not have an arrow the piston and rod assembly must have the wrist pin retainer facing the side of the engine Position the crankshaft crankpin at 90 to top dead center while sliding the piston assembly over the crankshaft Do not use force positioning the assembly diag 7 16 Install either a new crankcase cover O ring and lightly oil if one was originally used or apply Loctite 515 gasket sealant eliminator Tecumseh part 510334 to the crankcase surface to seal the crankcase cover Apply a continuous bead of Loctite 062 1 57 mm bead width on the crankcase surface The bead must completely surround the tapped holes for the cover Loctite must not enter the crankcase diag 7 17 Align the crankcase cover to the proper position using the mounting bolts as a guide Do not allow the cover to rotate while assembling Tighten the bolts to achieve 70 100 inch pounds 7 9 Nm 11 3 Nm of torque Instal
28. the starter pulley and tie a left handed knot in the end of the rope Wind the starter rope counterclockwise as viewed from the pulley bottom on the pulley and place the end of the rope in the notch in the pulley diag 5 5 Place the pulley in the blower housing press down and rotate the pulley until the pulley drops down and catches the end of the rewind spring On TC Type models continue assembly at step 7 diag 5 6 Lightly grease the pawl retainer and place the pawl with the numbers up on the retainer Place the brake spring on the center of the retainer with the tab locating the pawl diag 5 7 Install the retainer pawl and spring assembly on the center leg locate the notch in the center leg and the tab of the retainer and align when installing diag 5 8 Insert the retainer screw and torque to 30 40 inch pounds 3 4 Nm 4 5 Nm Use the starter rope or fingers to turn the pulley and pre wind the recoil spring a minimum of 1 3 4 and a maximum of 2 1 2 turns in counterclockwise rotation Feed the starter rope through the starter grommet and secure the starter handle using a left hand knot Retainer a SG Spring Tail CHAPTER 6 IGNITION GENERAL INFORMATION All TC TM engines are equipped with a solid state ignition module mounted outside the flywheel The solid state ignition system consists of a flywheel magnet charge coil capacitor a silicon controlled rectifier a p
29. the tool is flush with the crankcase diag 7 14 Later production TC engines have a step machined in the crankcase and crankcase cover bearing area This change eliminated the need for a retainer ring The bearing and seal installation tools part 670302 670303 670304A can be used with either style of crankcase cover The installation tools place the bearing in the cover or the crankcase to the proper depth Models equipped with a ball bearing in the crankcase cover can have the ball bearing removed using an arbor press with support placed near the bearing diameter Press the bearing out of the cover from the outside pushing the bearing away from the machined step A new crankcase cover ball bearing can be installed using an arbor press Press the bearing in until the bearing is flush and the bearing contacts the machined step Seal protector installer part 670303 should be used to install a new oil seal in the crankcase cover 40 Needle Bearing Cover Ball Bearing Cover Retainer Ring E S N Oil Seal LI N Bearing 3L ie SS Us N ASSEMBLY TC AND TYPE Il 1 Remove old gasket material Be careful not to damage scratch or burr the sealing surfaces Clean the crankcase cylinder piston assembly crankshaft and crankcase cover using cleaning solvent and blow dry with compressed air diag 7 15 On TC Type engines with a ball bearing on the P T O end assemble
30. 1041 TCH300 3305 200 701051 TC300 3031B 200 711021 TCH300 3305A 200 711031 TC300 3013C 200 721001 200 2103 200 731031 TC300 3013E 50 CHAPTER 9 EDUCATIONAL MATERIALS AND TOOLS TECHNICIAN S HANDBOOKS 692508 Covers the diagnosis and repair of Tecumseh 2 cycle engines Except the TC TM Engine and 840 850 692509 Covers the diagnosis and repair of the Tecumseh 4 cycle L head engines 691462A Covers the diagnosis and repair of Tecumseh 4 cycle cast iron engines 691218 Covers the diagnosis and repair of Peerless power train components 694782 Contains technical information for the repair of the TC TM series 2 cycle engines 694988 Contains diagnosis and technical information for the repair of 5840 HSK HXL845 850 2 cycle engines 695244A Covers the diagnosis and repair of the OHV 4 cycle overhead valve engines 695578 Covers the diagnosis and repair of the Vector VLV Series 4 cycle engines 696325 Covers the diagnosis and repair of the V Twin engines VIDEO PROGRAMS 69633 TVT VTX OV691EA This video provides a complete teardown and reassembly guide for the OV691EA 691 twin cylinder engine 695148 Teardown and reassembly of the 900 series transaxles This video will show a complete step by step procedure for teardown and reassembly of the 900 910 and 920 series transaxles 695285 An in depth look at the 800 series transaxles Detailing the teardown and reassembly procedures fo
31. D HOLDER A piece of 3 8 9 5 mm wood 1 1 2 38 1 mm wide by 4 101 mm long with a slot 3 8 9 5 mm wide by 2 50 mm long cut out of the center will hold the piston and rod SPARK TESTER 670366 RING COMPRESSOR 670391 52 ENGINE HOLDER 670300 To assist in reassembly of the engine block and its compo nents an Engine Holder part 670300 has been devel oped Attach to the crankcase of the engine with the blower housing base screws and insert the other end into a bench vise to hold crankcase while inserting engine components Use on TC200 Type and TC300 Type II engines 670300 AIR GAP GAUGE 670297 Used all TC200 Type TC300 Type Il rotary mower applications and all TM AIR GAP GAUGE 670321 Used on TC300 Type II non rotary mower engine applica tions SEAL PROTECTOR AND INSTALLER 670303 Used on the PTO oil seal TC Type 670303 BEARING INSTALLER 670304A Used to install the PTO bearing TC Type I II D 670304 SEAL PROTECTOR AND INSTALLER 670301 Used on the flywheel end oil seal TC Type I II TM 670301 BEARING INSTALLER 670302 Used to install the bearing in the flywheel end TC Type I II 53 SEAL PROTECTOR AND INSTALLER 670275 Used the PTO end oil seal TC TORX DRIVERS Torx 8 670334 Torx 10 670333 Torx 15 670323 Torx 20 670324 Torx 25 670319 Torx 30 670320 SPECIAL PART 510334 Loctite Gasket Sealant Eliminator No 515 will be sold by Tecums
32. ETOR Diaphragm Cover Screw Metering Diaphragm Cover Diaphragm Diaphragm Gasket Metering Lever Metering Lever Screw Metering Lever Pin Metering Lever Spring Inlet Valve Needle Air Vane Air Vane Screw 12 Dust Seal 13 Dust Seal Washer 14 Dust Seal Retainer 15 Idle Mixture Screw 16 Idle Speed Screw 17 Throttle Shaft 18 Throttle Shaft Return Spring 19 Throttle Shutter Screw 20 Throttle Shutter 21 Fuel Fitting 22 Fuel Inlet Screen 23 Pump Diaphragm 24 Pump Cover Gasket 25 Pump Cover 26 Pump Cover Screw 27 Tension Spring 28 Main Mixture Jet 29 Welch Plug ci WN 3 8 14 TECUMSEH CARBURETOR N amp Lo 12 13 14 15 16 17 18 19 20 2 22 23 24 25 26 27 Diaphragm Cover Screw Metering Diaphragm Cover Diaphragm Diaphragm Gasket Metering Lever Screw Metering Lever Pin Inlet Valve Needle Metering Lever Metering Lever Spring Welch Plug Dust Seal Dust Seal Retainer Dust Seal Retainer Screw Idle Mixture Screw Welch Plug Dust Seal Dust Seal Washer Throttle Shaft Return Spring Throttle Shutter Screw Throttle Shutter Fuel Fitting Pump Diaphragm Pump Cover Gasket Pump Cover Pump Cover Screw Idle Speed Screw Throttle Shaft 15 ENGINE TROUBLESHOOTING Engine Will Not Start See Chapter 6 Check For Spa
33. Hook the long end of the governor spring in the hole in the air vane and the short end in the hole in the speed control bracket The spring hooks from beneath both components Use the illustration diag 7 35 and the following spring location chart if the air vane has more than one governor spring hole and All TC300 Type II non rotary 0125 317 mm uses a colored spring with a square and round end mower use 030 762 mm part number 670297 Air gap part number 670321 All TC200 TC300 Type II rotary mowers and all TM 7 33 SPRING COLOR SPRING POSITION 21 Hook the upper fuel tank mounting tab over the blower housing stud and the carburetor studs Make sure the O ring is in position between the fuel tank and the carburetor Torque two hex nuts to 30 40 inch pounds 3 3 Nm 4 5 Nm See Carburetor Assembly instructions on page 22 Chapter 3 Install filter s and attach the air cleaner cover Connect the fuel line LATER TM Sleeve Spacers V at the tank position the fuel line clamp on the fuel can Through Hole Away fitting From Spark Plug Toward NOTE Carburetor Make sure sleeve spacers are installed If they are not M 25 nsulator installed the retaining nuts may loosen ASS b lt Spacer 22 Reset the governor and or speed control using the SS N 7 34 procedure in Chapter 4 under Service 23 Install the spark plug and connect the high tension lead Spring Position 2 CHAPTER 8
34. INKAGE GENERAL INFORMATION TC TM series engines are equipped with pneumatic air vane governors The governor s function is to maintain a R P M setting when engine loads are added or taken away Air vane governors are controlled by the air velocity created by fins on the flywheel Changes in the engine R P M cause the air vane to move This movement opens the throttle shaft either by alink between the air vane and the throttle plate or the air vane is mounted directly onto the throttle shaft The throttle is opened as the engine R P M drops and is closed as the engine load is removed This chapter includes governor assembly linkage and speed control illustrations to aid in assembly OPERATION Engine R P M changes cause an increase or decrease in the air velocity created by the fins on the flywheel The air velocity exerts pressure on the air vane while a governor spring exerts pressure against the air velocity force The air vane pivots on the engine blower housing base or is attached to the throttle shaft of the carburetor As an engine load is applied and the engine s R P M drop the air velocity also drops allowing the governor spring to pull open the throttle shaft and increase engine speed diag 4 1 If the engine uses a remote speed control the bowden wire will move the speed control plunger or the throttle shaft Moving the speed control plunger results in changing the governor spring tension which increases or decreases the
35. Or Shuts Off Restarts Check For Spark 5 SPARK sa NO SPARK Check compression release Replace spark plug for stuck open condition Isolate engine and repeat test Check flywheel for damaged or sheared key SPARK lt a 3 NO SPARK Equipment problem check switches wiring and equipment controls Engine problem check for shorts or grounds in wiring Set proper air gap on solid state module Disconnect ignition cut off wire at the solid state module and repeat test Test solid state module for intermittent or weak spark Check for proper air gap on solid state module and repeat test Fuel system problem see Chapter 3 Troubleshooting Check flywheel magnets for strength Test solid state module 31 TESTING 1 After repeated efforts to start the engine using the procedure listed in the operators manual fail check for spark by removing the high tension lead and removing the spark plug Install a Tecumseh spark plug tester part 670366 and check for spark If the spark is bright blue and fires every revolution proceed to step 2 If no spark weak spark or intermittent spark proceed to step 5 2 Check the spark plug for cracks in the porcelain pitted or burned electrodes excessive carbon build up and proper air gap setting Replace if questionable 3 engines pull out on compression release and crank the engine over If engine is not noticeably harder to crank ov
36. Personal Protective Equipment To avoid injury wear protective equipment including appropriate clothing eyewear safety shoes and ear plugs when servicing Tecumseh products B Stay Away from Rotat ing Parts Rotating parts can cause severe injury or death Use special care when making service adjustments with covers or guards removed Keep tools hands feet hair jewelry and clothing away from all moving parts Replace covers and guards before operating equipment Ok er a C Stay Away from Hot Sur faces Parts of equipment being serviced become extremely hot during operation and remain hot after the equipment has stopped To avoid severe burns stay away from hot surfaces or allow the unit to cool prior to service D Avoid Accidental Equipment Movement To prevent accidental movement of equipment always set the parking brake For gear driven products that do not have a parking brake leave equipment in gear and chock the wheels Refer to original equipment operator manuals for additional information Pulley bosses that hold the rewind spring inside the keeper and spring housing may not be secured and can be easily loosened Use special care when handling this housing Failure to do so could cause spring to fly out which could result in minor or moderate injury LAN Always discard gaskets O rings and seals after removal Use only new gaskets O rings and seals for assembly Failure to do so
37. RPM 777 erie AA ADJUST GOVERNED HIGH SPEED WITH SPEED CONTROL PLUNGER PULLED BACK AGAINST SPEED ADJUSTMENT SCREW DECREASE INCREASE FTE SPEED ADJUST SCREW GEG Spring Governor Clip Spring Spring and Link Attachment Speed Control Plunger Speed Adjustment Screw Notch in Air Vane for Governor Spring Attachment Speed Control Lever Spring Color Spring Position Orange or Green Pink Red or Black Spring Position 1 Spring Position 2 Speed Adjusting Screw CHAPTER 5 REWIND STARTERS GENERAL INFORMATION TC TM series engines have the recoil assembly as a part of the engine s blower housing Two different styles of recoil starters are used along with different starter rope locations Use the engine model and specification number to identify the recoil style and correct replacement parts OPERATION TC TYPE As the starter rope is pulled the starter pulley rotates on the center leg of the starter The starter pawl is connected to the starter pulley by an offset hole in the pawl and a corresponding raised boss on the pulley The pawl has an oversized inside diameter which allows the pawl to be pulled off center The flat contact surface of the pawl engages with one of the flywheel fins This engagement turns the flywheel until the engine fires and the flywheel speed exceeds the speed of the starter pulley The flywheel fins push the pawl using the ramp side to the
38. SBH Identification Number SBV 564A 2 SER 5107 Serial Number Short Block Identification Tag Tecumseh recommends using two cycle oil part 730227C which is a synthetic blend that ensures cylinder wall lubrication mixes easy and does not separate Two cycle oil part 730227C is specially formulated for use in air or water cooled two cycle engines and contains an added fuel stabilizer Tecumseh two cycle engines require the use of a NMMA TC W3 or TC WII certified oil The proper fuel mixture ratio of oil to gasoline for specific engines will be found in the Operator s Manual and on the decal attached to the blower housing or fuel tank of the engine FUEL REQUIREMENTS Tecumseh Power Company strongly recommends the use of fresh clean unleaded regular gasoline in all Tecumseh engines Unleaded gasoline burns cleaner extends engine life and promotes good starting by reducing the build up of combustion chamber deposits Leaded gasoline gasohol containing no more than 10 ethanol premium gasoline or unleaded gasoline containing no more than 15 MTBE Methyl Tertiary Butyl Ether 15 ETBE Ethyl Tertiary Butyl Ether or 10 ethanol can be used if unleaded regular gasoline is not available Reformulated gasoline that is now required in several areas of the United States is also acceptable NEVER USE gasoline fuel conditioners additives or stabilizers containing methanol The use of white gas gasohol containing more than 10 etha
39. TORS AND FUEL SYSTEMS 11 GENERAL INFORMATION es ue 11 OFERA TION mH PM 11 FUEL PRIMERS eei een 12 Sa ree rn E ee ee 13 ENGINE TROUBLESHOOTING sa une era eier da 16 TROUBLESHOOTING CARBURETION TC TM 5 17 TESTING za 19 SERVICE a a 19 CARBURETOR PRE SET AND ADJUSTMENT E24 4 22 Je 19 CARBURETOR DISASSEMBLY bodie nes lie enter 20 CARBURETOR INSPECTION Ze 20 BARBURETORASSEMBET aeg lcu ene ui 21 a NEED eiiis 24 CHAPTER 4 GOVERNORS AND 21 1111 nnn 25 GENERAL INFORMATION neat t ette Secale erui Peu 25 OPERATION pr Cresc ENS 25 COMPONEIN US 5 25 26 ENGINE OV ERSPEEDING nn nee 26 ENGINE SURGING LES 26 SERVICE ae RIED 26 GOVERNOR ADJUSTMENT 26 CHAPTER 5 REWIND STARTEBS es 28 GENERALINFORMATIONE See ee ee ee Rdn 28 BRERATION RE 28
40. a building with potential sources of ignition such as hot water and space heaters clothes dryers electric motors etc NEVER remove fuel cap or add fuel when engine 1 running NEVER start or operate the engine with the fuel fill cap removed Allow engine to cool before refueling NEVER fill fuel tank indoors Fill fuel tank outdoors in a well ventilated area DO NOT smoke while refueling tank DO NOT pour fuel from engine or siphon fuel by mouth K Avoid Accidental Starts To prevent accidental starting when working on equip ment always Disconnect spark plug wire and keep it away from spark plug Keep the disconnected spark plug wire securely away from metal parts where arcing could occur e Attach the spark plug wire to the grounding post if provided Turn off all engine switches ENGINE IDENTIFICATION Engine Model Families This Tecumseh Technician s Handbook covers the following engine model types e C200 Two Cycle Engine Type 2 0 cubic inch displacement e C300 Two Cycle Engine Type II 3 0 cubic inch displacement e MOA9XA Two Cycle Engine Multi Position 49cc displacement The letter designations in a model number indicate the basic type of engine See diag 1 4 The number designations following the letters indicate the basic engine model The number following the model number is the specification number The last three numbers of the specification number indicate a v
41. aining clip and throttle shaft On some older Walbro carburetors it is necessary to remove the circlip on the end of the throttle shaft to remove the shaft diag 3 11 Remove the inlet needle valve metering lever and metering lever spring by removing the retainer screw on the pivot pin diag 3 11 Remove the fuel inlet screen and check valve screen using an O ring pick Remove all welch plugs using a sharpened small chisel Drive the sharpened chisel into the welch plug push down on the chisel to pry the welch plug out of position Be careful not to damage the carburetor body diag 3 12 On Walbro carburetors the fuel inlet fitting can be removed with a pliers using a twisting and pulling motion Do not re use the old fuel fitting The fuel fitting on Tillotson carburetors is not replaceable Do not remove Carburetor cleaner will not affect this fitting Clean all metallic parts in carburetor cleaner Do not exceed 30 minutes soak time Blow out all fuel passages with compressed air Do not use tag wire to clean the orifice in the main mixture seat assembly The main mixture seat assembly contains a teflon disc check valve If the disc is damaged with tag wire the carburetor will not function properly CARBURETOR INSPECTION Visually examine the throttle lever shaft and choke shaft for wear at the bearing points in the carburetor body Inspect the pump and metering diaphragms for hardness fuel contaminati
42. an ring ina machined channel TM engines have been upgraded to include a manual compression release Engines requiring replacement of the cylinder cylinder cover crankcase or piston and rod assembly may require the replacement of the short block or a complete engine Consult the Tecumseh Master Parts Manual Microfiche or Electronic Parts Catalog using the engine model and specification number for replacement part information DISASSEMBLY PROCEDURE TC TYPE I AND TC TYPE Il 1 Remove the high tension lead boot from the spark plug by twisting and pulling 2 Remove the spark plug using a 3 4 19 mm deep well socket 3 Drain the fuel from the tank by sliding the fuel line clamp off the carburetor fuel fitting TC Type or fuel tank fitting TC Type Il twist and pull the fuel line off and drain the fuel into an approved container outdoors and away from any open flame or combustion source be sure the engine is cool To avoid death or serious injury DO NOT pour fuel from engine or siphon fuel by mouth 38 4 Remove the two hex nuts on the carburetor studs and remove the air cleaner assembly On TC Type Il engines remove the two screws on the filter cover the filter element s and then the two hex nuts on the carburetor studs If the carburetor stud loosens try retightening the hex nuts first then loosen the nuts 5 Remove the fuel tank on TC Type engines by unhooking the tank spring For Type II engines remove the
43. ariation to the basic engine specification The serial number or D O M indicates the production date of the engine TC engine identification numbers are stamped into the blower housing or blower housing base near the spark plug or a decal is permanently attached to the side of the blower housing See diag 1 1 Identification Decal TYPE Il and TM ENGINES The engine identification decal will include the model number engine type warranty code and date of manufacture See diag 1 2 and 1 3 The model number designation following TC Tecumseh Compact indicate the cubic inch displacement of the engine TC300 indicates 3 0 cubic inch displacement The number 3133C following the model number is the specification number The last two numbers and letter character 33C indicate a variation to the basic engine specification The warranty code letter B indicates the length of warranty that is supplied by Tecumseh The DOM Date of Manufacture or Serial Number indicate the date the engine was produced The first digit 5 is the year in the decade 1995 The next three digits 114 indicate the build date 114th day of the year or April 24 The letter designation indicates the line or shift on which the engine was built at the factory Short blocks are identified by a tag marked SBH Short Block Horizontal or SBV Short Block Vertical See diag 1 5 I 200 Models sample 200 decal is pictured for reference See
44. ceptacle remove the fuel line from the carburetor inlet fitting TC Type 1 or fuel tank TC Type TM and pull off the fuel line Examine the fuel flow and fuel condition Improper fuel flow indicates the fuel fuel line filter or tank require cleaning or replacement Visually inspect the choke shutter for complete closing or check to see fuel flowing from the main nozzle during priming Remove the air cleaner element or air cleaner assembly to provide access for visual inspection If the fuel flow to the carburetor is adequate and no fuel flows out the main nozzle during priming or choking the carburetor will require service Consult the Troubleshooting Carburetion Chart for possible causes for the lack of fuel Check the compression release on TM engines Low compression no fuel present on the spark plug adequate fuel flow and a known good functional carburetor indicates an internal engine problem exists See Chapter 7 under Troubleshooting Check the engine compression using compression tester part 670358 and follow the tester s recommended procedure Low compression no fuel present on the spark plug adequate fuel flow and a known good functional carburetor indicates an internal engine problem exists See Chapter 7 under Troubleshooting 3 10 Walbro model WTA WT 1 1 1 8 turns Tillotson model HU 1 1 4 1 3 8 turns Tecumseh model Fixed Final Idle Mixture Adjustment Start the engine and allo
45. could result in leakage from engine areas that use these parts E Always Provide Adequate Ventilation To avoid serious injury or death always ensure that you are working in a properly ventilated facility Special precautions are required to avoid car bon monoxide poisoning All engine exhaust contains carbon monoxide a deadly gas Breathing carbon monoxide can cause headaches dizziness drowsiness nausea confusion and eventually death Carbon monoxide is a colorless odorless tasteless gas which may be present even if you do not see or smell any engine exhaust Deadly levels of carbon monoxide can collect rapidly and you can quickly be overcome and unable to save your self Also deadly levels of carbon monoxide can linger for hours or days in enclosed or poorly ventilated areas If you experience any symptoms of carbon monoxide poi soning leave the area immediately get fresh air and SEEK MEDICAL TREATMENT To prevent serious injury or death from carbon monoxide ALWAYS direct engine exhaust outdoors e NEVER run engine outdoors where engine exhaust can be drawn into a building through openings such as windows and doors F Use Proper Methods When Cleaning To reduce the risk of serious injury or death from fires and or explosions NEVER use flammable solvents e g gasoline to clean serviceable parts Use a water based non flammable solvent such as Tecumseh Degreaser Cleaner G Compressed Air Precauti
46. der Service 7 Check for the correct ignition module air gap See Chapter 6 under Service 8 Inspect the intake gaskets crankcase seals or gaskets for a leaking condition Use a commercially available crankcase pressure tester and follow the tester s recommended test procedure See Disassembly Procedure in this chapter for component removal SURGES OR RUNS UNEVENLY 1 2 3 Check the fuel cap to make sure it is venting Loosen the cap and retry engine operation Replace or clean the air filter if applicable Check the carburetor for the correct idle mixture adjustment Clean the carburetor if the problem persists See Chapter 3 under Service Check the engine R P M setting using a Vibratach or other tachometer and compare it to the R P M settings found on microfiche card 30 or computer parts lookup according to the engine model and specification number Adjust as necessary Visually check all linkages Check the governor spring for a stretched or damaged condition Check the governor shaft throttle shaft and pivot points for binding Check the ignition module operation using a Tecumseh 670366 Spark Tester inserted in the high tension lead Check for intermittent spark Inspect the intake gaskets crankcase seals or gaskets for a leaking condition Use a commercially available crankcase pressure tester and follow the tester s recommended test procedure See Disassembly Procedure in this chapter for component removal
47. eh under the part 510334 VIBRATION TACHOMETER 670156 METERING LEVER GAGE 670325 Used to set carburetor metering lever 54 ME TERING VER GAGE 670275 This manual covers all TC and TM models Other illustrated Tecumseh 2 Cycle Engine 4 Cycle Engine and Transmission Technician s Handbooks and wall charts are available through Tecumseh For complete listing write or call _ TECUMSEH ENGINES amp TRANSMISSIONS Tecumseh Power Company Tecumseh Europa 5 740109 900 North Street Strada delle Cacce 99 Grafton WI 53024 10135 Torino Italy Phone 262 377 2700 Tel 39 0 11 391 8411 262 377 4485 Telefax 39 0 11 3910031 www TecumsehPower com Form No 694782 Rev 1 05 Litho in U S A
48. er 100 PSI Lower compression requires less effort to be used for operation of the rewind starter which allows for easier starting As the engine starts the pressure inside the cylinder builds and automatically pops the yellow button of the compression release out to the CLOSED position allowing the engine to run at full compression The yellow compression release button must be pushed in for each pull of the starter rope diag 7 2 Over time it may be necessary to remove the valve assembly for cleaning The valve should only be removed when the engine is fully cooled DO NOT TRY TO DISASSEMBLE THE VALVE After removal from the engine open the valve by depressing the yellow knob and spray with carb amp choke cleaner Allow to soak for 10 to 15 minutes and blow compressed air through the valve assembly Repeat this process if the valve does not operate freely Reinstall the valve and tighten to the recommended torque COMPRESSION RELEASE 33 COMPONENTS 1 CYLINDER 522 3 PISTON PIN 4 PISTON 5 ROD 2 6 CRANKCASE 7 CRANKSHAFT 1 CYLINDER CRANKCASE 2 PISTON RINGS 3 CRANKSHAFT ASSEMBLY 4 CRANKCASE COVER 5 FLYWHEEL SEAL 6 PTO SEAL TROUBLESHOOTING ENGINE OPERATION PROBLEMS ENGINE VIBRATES EXCESSIVELY Wrong or fouled spark plug Bent crankshaft Carburetor improperly adjusted Attached equipment out of ba
49. er Remove the flywheel nut washer flywheel and flywheel key diag 7 25 NOTE Do not use a knock off tool on the crankshaft when removing the flywheel Permanent engine damage may result 10 Mark or note the location of the throttle link governor spring hook up and speed control to aid in assembly Remove the carburetor spacer gaskets and air baffle if equipped 11 Remove the blower housing base by removing the three 5 16 hex head screws and if equipped the two 1 4 hex head screws for the muffler heat shield 12 Place engine in a soft jawed bench vise NOTE DO NOT over tighten engine in vise Permanent engine damage may result 13 Remove the two shoulder bolts holding the muffler and remove the muffler 14 Remove the compression release valve using a 1 2 deep socket 15 Remove the four Torx bolts holding the crankcase halves together using Torx T30 driver part 670320 Remove the crankcase cover diag 7 26 16 Pull the crankshaft piston and rod assembly squarely out of the cylinder using caution so the rod does not bend diag 7 27 17 Remove both oil seals from the crankshaft BEARING AND SEAL SERVICE TM The crankshaft bearings can only be replaced as part of the crankshaft piston and rod assembly Follow the Disassembly and Assembly procedures for TM engines The crankshaft oil seals can be replaced by separating the crankcase and cover Follow the Disassembly and Assembly
50. er replace or clean the compression release mechanism See Chapter 7 under Service 4 Check the air gap between the ignition module and the flywheel magnet See Service in this chapter 5 Disconnect the ignition grounding lead at the ignition coil and crank the engine over spark occurs check the ignition switch or the electrical wiring for shorting to ground If no spark test the ignition module using a coil tester or replace the ignition module SERVICE AIR GAP SETTING Timing on the solid state module is fixed The air gap dimension between the laminations of the ignition module and the magnet is 0125 317 mm use gauge part 670297 for all TC200 engines TC300 Type II rotary mower engines and all TM All other TC300 Type II applications require a 030 762 mm air gap dimension use gauge part 670321 Loosen the module mounting bolts insert the air gap gauge hold the module against the flywheel magnets and torque the mounting screws to the specification Remove the gauge and rotate the flywheel to check for any possible striking points If none are found the air gap is set correctly diag 6 3 NOTE When using the 670321 gauge push the module tight to the flywheel before tightening SPARK PLUG SERVICE Spark plugs should be removed cleaned and gap adjusted periodically If the porcelain shows cracking or the electrodes show evidence of pitting burning or excessive carbon build up replace the spark plug
51. es for a complete cycle that occurs every crankshaft revolution while four cycle engines use four piston strokes and two crankshaft revolutions for a complete cycle Lubrication is accomplished through oil mixed in the fuel and the air fuel oil mixture flows into the crankcase during upward piston travel This mist lubricates all internal bearing surfaces OPERATION A low pressure area is created in the crankcase as the piston moves upward to compress the air fuel mixture in the cylinder When the piston moves far enough to uncover the intake port the air fuel mixture from the carburetor flows into the engine crankcase due to higher pressure atmospheric air Just before the piston reaches top dead center TDC the spark plug ignites the air fuel mixture in the cylinder The expanding combustion gases force the piston down The downward piston travel causes a pressure build up in the crankcase The piston uncovers the exhaust port first followed by the transfer ports The exhaust flows out the exhaust port while the pressurized air fuel mixture enters the cylinder from the crankcase through the transfer ports As the piston travels upward the sequence is repeated diag 7 1 MANUAL COMPRESSION RELEASE TM engines are equipped with a manual compression release located in the head near the spark plug Pushing the yellow button of the compression release in to the OPEN position lowers the cylinder compression to und
52. f position 670156 or other tachometer determine the engine s R P M at idle and wide open throttle Consult microfiche card 30 or the computer parts lookup to obtain the recommended engine speeds Using the applicable illustration either bend the speed adjusting lever toward the spark plug end of the engine to decrease high speed R P M or bend the lever in opposite direction to increase R P M On TC Type engines turn the speed adjusting screw out to increase or in to decrease engine high speed R P M If the soeed adjustment screw is turned out to increase the engine R P M the speed control lever must be moved to allow the speed control plunger to contact the speed adjustment screw The low speed is set by moving the throttle control to the lowest speed position and adjusting the low speed adjustment screw on the carburetor Adjusting Lever Decrease Increase TYPE I and EARLY TC TYPE Il Spring Hooked In Notch TC TYPE I and some TC Type Il AIR VANE MUST ROTATE FREELY AFTER CLIP IS INSTALLED DESCRIPTION Base Housing Body Assy Speed Control Screw Carburetor Throttle Plate Air Vane Spring Backlash Link Governor TYPE Decrease IN Increase OUT Speed Adjusting Screw Adjust governed high speed with speed control plunger pulled back against speed adjustment screw Turn speed adjusting screw IN to decrease engine RPM or OUT to increase
53. gaskets spacer and carburetor Assemble gaskets correctly do not block the pulse passage Torque the two hex nuts to 30 40 inch pounds 3 3 Nm 4 5 Nm See Carburetor Assembly instructions on page 22 Chapter 3 On later TM engines install long carburetor screws through the back of the spacer Ensure that hex heads of the screw are properly seated in the spacer Install the air baffle gaskets and spacer on the engine Install gaskets correctly do not block the pulse passage Torque the two hex screws to 30 40 inch pounds 3 3 Nm 4 5 Nm Install the flywheel key and flywheel Install the flywheel washer and nut use a strapwrench part 670305 to hold the flywheel and torque the nut to 15 20 foot pounds 1 6 Nm 2 2 Nm Go to next page 46 17 Attach the ignition module use the air gap gauge between the flywheel magnets and the module laminations use 0125 317 mm gauge part 670297 Torque the module mounting screws to 30 40 inch pounds 3 3 Nm 4 5 Nm Remove the air gap gauge rotate the flywheel to assure it does not strike the ignition module Attach ignition grounding lead to the module terminal diag 7 33 18 Install the blower housing and rewind assembly Replace the debris guard if applicable diag 7 33 19 On later TM engines install gasket and carburetor Install sleeve spacers over carburetor screws diag 7 34 20
54. h the inlet needle into the metering chamber FUEL PRIMERS Primers used on TC TM engines supply a solid fuel charge to the carburetor main nozzle diag 3 6 Fuel is forced directly into the carburetor venturi A choke shaft and shutter is not needed or used when a primer is used This charge of fuel provides the rich mixture necessary to start the engine Below the main nozzle is a one way check valve to prevent fuel from being drawn back into the fuel chamber when the primer bulb is released The check valve also prevents air from entering the carburetor during normal engine operation 12 Fuel Impulse Intake Air Engine Vacuum Fuel Impulse Intake Air Engine Vacuum Intermediate Fuel Impulse Intake Air Engine Vacuum High Speed COMPONENTS WALBRO CARBURETOR 1 Diaphragm Cover Screw Metering Diaphragm Cover Diaphragm Diaphragm Gasket Metering Lever Metering Lever Screw Metering Lever Pin Metering Lever Spring Inlet Valve Needle Inlet Valve Seat Welch Plug Choke Shaft Choke Shutter Screw Choke Shutter Idle Mixture Screw Idle Speed Screw Throttle Shaft Throttle Shaft Return Spring Throttle Shutter Screw Throttle Shutter Fuel Fitting Fuel Inlet Screen Pump Diaphragm Pump Cover Gasket Pump Cover Pump Cover Screw Tension Spring Dust Seal Dust Seal Washer 13 TILLOTSON CARBUR
55. is recommended every three 3 months or every 25 operating hours If the engine is used in extremely dusty Da or dirty conditions the filter may require service every te F Collar three hours or as often as necessary to maintain proper 72 NE engine performance Air Cleaner Screen Air Cleaner Polyurethane type filters require re oiling after extended storage due to oil migration out of the filter A paper type element diag 2 2 should be replaced once a year every 100 operating hours or more often if used in extremely dusty conditions Use only original factory recommended replacement filters NOTE DO NOT attempt to clean or oil paper filters Paper Filter Removal and Replacement 1 Inspect the Remove the polyurethane pre filter if equipped from the air filter filter s for discoloration dirt accumulation For the polyurethane pre cleaner service see step 5 under Polyurethane Filter Removal and Service If either condition is present replace the paper type filter using the following steps Loosen the clamp and slide the clamp toward the air filter diag 2 3 Slide the air filter and clamp off the carburetor adapter Discard the old filter and keep the clamp Apply a thin layer of silicon sealant to the outside of the air cleaner adapter Install the clamp on the new air filter slide the filter assembly onto the carburetor adapter as far as it will go Slide the cla
56. l the crankcase oil seal using seal protector part 670301 on crankcase oil seal The metal case of the seal must face toward the tool Press the tool flush to the crankcase Install crankcase cover oil seal using seal protector installer part 670303 to protect the oil seal during installation The metal case of the seal must face toward the tool Press the tool flush to the cover Apply mineral spirits or kerosene to the crankpin bearing and rotate the crankshaft to dissolve the wax of a new needle bearing strip Apply engine oil and rotate the crankshaft to displace the grease used to hold the needles in place on grease retained crankpin bearings Install cylinder gasket notched edge toward the cylinder cover and the exhaust port side of cylinder or apply a 062 1 57 mm bead of Loctite 515 to the cylinder crankcase surface if Loctite was originally used The Loctite bead must completely surround the cylinder bolt holes Loctite must not be allowed to enter the crankcase STRIP OF NEEDLE BEARINGS SOME MODELS WS MY s SS MEY N N 2 062 1 ib mm Se an Bead of Loctite 7 17 41 10 11 12 13 14 15 42 Use a piston and rod holder dimensions are in Chapter 9 tool section to prevent damage to the rod when installing the cylinder Make sure the ring end gaps are staggered and the cylinder is in the correct position Use fingers or ring compressor
57. lance Loose mounting bolts Ignition timing Excessive carbon build up Leaking seals or gaskets LACKS POWER or WILL NOT START Air intake obstructed Lack of lubrication or improper lubrication Carburetor improperly adjusted Exhaust obstructed Loss of compression Crankcase seals or gaskets leaking Choke throttle or governor not operating properly Ignition timing Carb gasket damaged or installed incorrectly Compression release stuck open 35 TROUBLESHOOTING ENGINE OPERATION PROBLEMS ENGINE KNOCKS OVERHEATS SURGES OR RUNS UNEVENLY Associated equipment loose or Excessive engine loading Fuel cap vent obstructed improperly adjusted Check for excessive carbon in Lack of or improper lubrication Dirty carburetor or air filter combustion chamber Loose flywheel examine key Cooling air flow obstructed or Carburetor improperly adjusted keyway and proper flywheel nut clogged cooling fins torque Carburetor improperly adjusted or Govemor sticking binding or Ignition timing improper R P M setting Worn Crank Pin Journal Ignition timing Carburetor linkage shafts or shutters sticking or binding Worn cylinder or piston Carbon in the combustion chamber Intermittent spark check ignition Offset piston incorrectly installed Leaking seals or gaskets 36 TESTING ENGINE KNOCKS 1 Check the blade hub adapter crankshaft coupler or associated equipment for loose fit or lo
58. mbly Defective Gasket Loose Diaphragm Rivet Hole in Diaphragm Loose Cover Screws INLET NEEDLE amp SEAT Foreign Matter Binding Worn Needle Body or Tip NOZZLE CHECK VALVE 18 TESTING 1 SERVICE CARBURETOR PRE SET AND ADJUSTMENT The Walbro Tillotson and Tecumseh carburetors used on TC engines have non adjustable main mixture jets Only the idle mixture may be adjustable by turning the idle mixture screw Use the following procedure to pre set the idle mixture screw Turn the idle mixture screw clockwise finger tight to the closed position then turn the screw counterclockwise to obtain the proper preset diag After repeated efforts to start the engine using the procedure listed in the operator s manual fail check for spark by removing the high tension lead and removing the spark plug Install a Tecumseh Spark Plug Tester part 670366 and check for spark If the spark is bright blue and fires every revolution proceed to step 2 If no spark weak spark or intermittent spark see Chapter 6 Ignition under Troubleshooting Remove the spark plug and visually check the removed spark plug for a wet condition indicating the presence of fuel mixture in the cylinder If the spark plug is dry check for restrictions in the fuel system before the carburetor If the spark plug is wet continue with step 7 Check the fuel cap vent the cap must allow air to be blown through it when testing Using a proper draining re
59. mp as close to the carburetor as possible Tighten the clamp securely Polyurethane Filter Removal and Service Kleen Aire Air Cleaner TC Type or TM da 10 Remove the cover by pulling outward on the tab diag 2 4 On the TC Type style engine loosen the two screws diag 2 5 Remove screen A if equipped foam filter and screen B from the air cleaner body diag 2 4 On TC Type II TM engines remove the flocked screen and the foam filter diag 2 5 Inspect the flocked screen and foam filter for discoloration or dirt accumulation If either condition is present service the element or screen using the following steps The flocked screen pre filter may be cleaned by blowing compressed air through the screen from the back side Replace the screen if this procedure does not fully remove the accumulated particles Wash the polyurethane filter or polyurethane pre filter used with paper air filters in a detergent water solution and squeeze dont twist until all dirt is removed Rinse the polyurethane filter or polyurethane pre filter thoroughly in clean water Wrap the filter in a clean cloth and squeeze don t twist until completely dry Reassemble the filter assemblies per the illustrations Poly Pre Filter Air Cleaner Clamp Carburetor Adapter Carburetor Screen A Screen B Polyurethane Filter amp Lock Nut TC TYPE Washer
60. ng compressor diag 7 29 Do not rotate or twist the crankshaft assembly Insert the piston until the crankshaft bearings seat in the crankcase PTO end bearing retaining ring must seat in groove of crankcase diag 7 30 45 10 11 12 13 14 15 16 Clean both gasket surfaces using isopropyl alcohol before application of the gasket eliminator Apply Loctite 515 gasket sealant eliminator Tecumseh part 510334 to the crankcase surface to seal the crankcase cover Apply a continuous bead of Loctite 062 1 57 mm bead width on the crankcase surface according to the pattern Loctite must not enter the crankcase diag 7 31 Align the crankcase cover to the proper position using the mounting bolts as a guide Once cover screws are snug tap cover down using a soft mallet to help displace the gasket eliminator Torque cover screws to recommended torque specifications Tighten the bolts to achieve 105 inch pounds 11 8 Nm of torque diag 7 32 Install the compression release Torque to 100 inch pounds 11 3 Nm Install the exhaust gasket muffler spark arrestor if applicable and bolts Torque the muffler bolts to 110 inch pounds 12 4 Nm Attach the blower housing base using three screws and torque the screws to 30 40 inch pounds 3 3 Nm 4 5 Nm Attach and torque the air vane to the carburetor throttle shaft before installation On early TM engines install the air baffle
61. nol unleaded regular gasoline containing more than 15 MTBE Methyl Tertiary Butyl Ether 15 ETBE Ethyl Tertiary Butyl Ether or 10 ethanol is not recommended as engine fuel system damage could result See STORAGE instructions in Technician s Manual Operators Manual or Bulletin 111 Tecumseh two cycle oil part 730227C contains a fuel stabilizer for year round fuel stability in and out of season If oil other than Tecumseh two cycle is used use Tecumseh s fuel stabilizer part 730245 MIXING FUEL AND OIL Table 1 4 Fuel Mix Chart Mixture Ratio 24 1 NEVER store engine with fuel in fuel tank inside a building with potential sources of ignition such as hot water and space heaters clothes dryers electric motors etc DO NOT mix fuel and oil directly in fuel tank 11 oz 333 ml Use of NUMA or TC W3 JASO FB or JASO 20 Liters 833 ml classified oil is recommended 1 Be sure container is outdoors and in a well ventilated area Table 1 5 Recommended Fuel 2 Fill approved clean red GASOLINE container with 1 4 of recommended fuel amount See Table 1 4 and Dueb HCHO AMEN Table 1 5 Ethanol 10 3 Add required amount of recommended oil to fuel Grain Alcohol Gasohol oee Table 1 4 MTBE Methyl Tertiary Butyl Ether Screw cap onto container ms ETBE Ethyl Tertiary Butyl Ether Shake container vigorously Unscrew cap from container PE Fill container with remainder of rec
62. ommended fuel See Table 1 4 and Table 1 5 8 Wipe away any spilled fuel or oil FUEL ADDITIVES Only fuel additives such as Tecumseh s fuel stabilizer part 730245A or liquid varieties can be used when mixed properly For winter applications Isopropyl alcohol fuel dryers may be used in the fuel system but must be mixed at the proper ratio recommended by the manufacturer NEVER USE METHANOL BASED DRYERS Gasoline and oil containers must be clean covered and rust free Old gas or fuel contamination can restrict or block fuel filters and small fuel ports and passages in the carburetor If the engine is to be unused for 30 days or more see Storage for fuel system instructions TUNE UP PROCEDURE The following is a minor tune up procedure If the engine does not perform properly after the tune up is completed consult the Troubleshooting Engine Operation Chart found in Chapter 7 Repair procedures are listed in each chapter Remove the spark plug wire before doing any service work on the engine 1 Service or replace the air cleaner as necessary Use the applicable procedure found in Chapter 2 under Service 2 Remove the fuel from the fuel tank by running the engine until stopping or draining into an approved fuel container 3 Remove the fuel tank and blower housing to clean all debris from the air intake screen cylinder cooling fins governor and carburetor linkage Replace the blower housing and check all remote linkage for
63. on holes or tearing in the diaphragm Pump diaphragm flapper valves should appear flat with no curling Check the inlet screen and check valve screen for contamination Check the atmospheric vent hole in the metering cover and clean if necessary Check the inlet needle for wear on the taper portion of the needle Replace as necessary 20 A Dust Seal Retainer Metering Lever Metering Lever Pin M ed Lever Screw Metering Lever Spring Tension Spring Idle Mixture Needle Screw N a h PI 4 Wb elch Plu Fuel Inlet gt 1 Main Mixture Jet Throttle Screen 2 e Shutter Throttle Screw Shutter N Dust Seal NND Dust Seal Washer Inlet Valve Throttle Shaft Return Spring 7 Throttle Shaft Note Do not allow chisel point to strike carburetor body or channel reducer Pierce plug with tip Welch Plug Small Chisel CARBURETOR ASSEMBLY 1 Install new inlet screen s using a small flat punch slightly smaller than the screen Push in until the screen contacts the seat removed install the high speed jet Use a slightly larger flat punch to install the brass welch plug over the high speed jet The closed tapered end of the plug goes toward the jet Tap the brass welch plug in until it is flush with the carburetor body Apply sealant like fingernail polish to the brass plug Install new welch plug s using a flat punch equal to or slightly larger than the pl
64. ons Never use compressed air to clean debris from yourself or your clothing When using compressed air to clean or dry serviceable parts Wear appropriate eye protection Use only approved air blow nozzles Air pressure must not exceed 30psi 206kPa e Shield yourself and bystanders from flying debris H Inspect and Adjust Brake s Always inspect and adjust flywheel brake components whenever servicing equipment that has a Tecumseh engine Refer to this 5 Handbook and bulle tins for proper brake adjustment I Operate Equipment Safely Operation of equipment presented for service can be hazardous To avoid serious injury or death DO NOT operate equipment until all relevant inspection procedures presented in this handbook are performed and e technician is satisfied equipment can be operated safely e Starter pulley springs hold the starter rope and control tension by winding the rope around the pulley Use caution when pulling and releasing the rope to and from the starter housing Failure to do so could cause the rope to unexpectedly jerk back which could result in minor or moderate injury J Avoid Gasoline Fires Gasoline fuel vapors are highly flamma ble and can explode Fuel vapors can spread and be ignited by a spark or flame many feet away from engine To prevent injury or death from fuel fires follow these instructions NEVER store engine with fuel in fuel tank inside
65. oper fuel flow and engine operation To prevent deposits from forming all gasoline must be removed from the fuel tank and the carburetor An acceptable alternative to removing all gasoline is adding a fuel stabilizer to the gasoline such as Tecumseh part 730245A A fuel stabilizer is added to the fuel tank or storage container Always follow the mix ratio and mixing procedure found on the stabilizer container Run the engine at least 10 minutes after adding the stabilizer to allow it to reach the carburetor Draining The Fuel System 1 Remove all gasoline from the fuel tank by running the engine until the engine stops or by draining the fuel tank by removing the fuel line at the carburetor Be careful not to damage the fuel line or the carburetor fitting Drain the fuel into an approved container outdoors and away from any open flame or combustive source Be sure the engine is cool To avoid death or serious injury DO NOT pour fuel from engine or siphon fuel by mouth If Gasohol has been used complete the above procedure and then put 2 ounces 60 ml of the recommended fuel oil mixture using regular unleaded gasoline into the fuel tank Run the engine until it stops due to a lack of fuel If Gasohol is allowed to remain the fuel system during storage the alcohol content may cause gaskets and seals to deteriorate Oil Cylinder Bore 1 Remove the spark plug wire from the spark plug Pull the starter handle slowly until resis
66. ose bolts Re install and re torque the bolts to the proper torque 2 Check the flywheel key and the flywheel and crankshaft keyway for wear or partial shearing Replace if any damage is evident Tighten the flywheel nut to the proper torque 3 Check for the correct ignition module air gap See Chapter 6 under Service 4 Remove the muffler and check for carbon build up in the combustion chamber and exhaust port Check the spark plug for the proper reach and heat range correct spark plug for the engine Clean carbon build up if necessary 5 Check the internal components piston cylinder and crankshaft journals for excessive clearance ENGINE OVERHEATS 1 Make sure the engine is not being overloaded Remove excess load 2 Make sure the fuel mixture contains the correct ratio of certified 2 cycle oil to gasoline Replace the fuel supply if questionable Check for clogged cooling fins or obstructions to the air flow Remove the rewind assembly clean and reinstall Check the engine R P M setting using a Vibratach or other tachometer and compare it to the R P M settings found on microfiche card 30 or computer parts lookup according to the engine model and specification number Adjust as necessary 5 Remove the muffler and check for carbon build up in the combustion chamber and exhaust port Clean as necessary 6 Check the carburetor for the correct idle mixture adjustment Clean the carburetor if the problem persists See Chapter 3 un
67. ove the fuel tank spring and recoil assembly from the engine On TC Type II TM engines the air filter and fuel tank must be removed before the recoil assembly 28 2 Release the recoil spring tension on the rope by removing the staple or knot in the starter handle and slowly release the rope into the recoil housing diag 5 2 Remove the 5 16 retainer screw On TC Type starters remove the pawl retainer brake spring and pawl Remove the starter pulley CAUTION Be careful not to pull the rewind spring out of the blower housing when removing the starter pulley The rewind spring will uncoil and expand with force if removed from the blower housing which can Cause serious injury ASSEMBLY PROCEDURE 1 Lightly grease the center leg and the area where the rewind spring will rest in the blower housing with Chem Lube or Lubriplate diag 5 3 Install a new starter spring if necessary Securely grip the rewind spring a short distance away from the spring tail with a needlenose pliers Position the rewind spring in the blower housing and hook the spring tail to the housing as shown Make sure the spring tail is fully seated before slowly releasing the needlenose pliers from the spring Push the coiled spring into the recessed boss area and discard the spring holder Apply a thin coating of Chem Lube to the top of the spring diag 5 4 Insert the starter rope into
68. r add the pump diaphragm next and place the assembly on the carburetor body Check to see that the locator pins fit the corresponding holes in the carburetor body Install the pump cover retaining screw diag 3 15 removed on Walbro carburetors install a new fuel inlet fitting in the same position as the original diag 3 15 When installing a new fitting insert the tip into the carburetor body then coat the exposed portion of the shank with Loctite grade A red then press it in squarely using support on the opposite side to prevent damage to the carburetor body or fitting Press it in until the fitting bottoms out in the carburetor body Note Punch should be of the same or larger diameter than the welch plug __ Flat End New Welch Inlet Needle Metering Pin Metering Lever Tip Metering Diaphragm Cover Diaphragm 3 Diaphragm Gasket Pump Diaphragm Pump Cover Gasket Pump Cover of the choke and throttle 10 Install the choke and throttle shaft assemblies in the reverse order of removal Visually check for proper operation 12 TC and TM series engines use an insulator spacer between the carburetor and cylinder That spacer MUST be position of the spacer block 11 If applicable attach the air vane and torque the mounting screw to 3 5 inch pounds 34 Nm 57 Nm installed correctly for the fuel pump to operate diag 3 16 Use the appropriate style to determine the correct
69. r housing base Hook the long end of the governor spring into the notch on the neck of the air vane The short end hooks into the hole in the speed adjusting lever as shown diag 7 20 Insert one end of the throttle link in the hole in the air vane and the other end in the hole closest to the throttle shaft Install the air baffle if equipped gaskets spacer and carburetor See Carburetor Assembly instructions on page 22 Chapter 3 Assemble gaskets correctly do not plug the pulse passage Torque the bolts to 30 40 inch pounds 3 3 Nm 4 5 Nm On TC Type II models attach and torque the air vane to the carburetor throttle shaft before installation Hook the long end of the governor spring in the hole in the air vane and the short end in the hole in the speed control bracket The spring hooks from beneath both components Use the illustration diag 7 21 and the following spring location chart if the air vane has more than one governor spring hole and uses a colored spring with a square and round end SPRING COLOR SPRING POSITION Orange orGreen 1 Spring Position 1 Spring Position 2 16 17 Install the flywheel key and flywheel Install the flywheel washer and nut use a strapwrench part 670305 to hold the flywheel and torque the nut to 15 20 foot pounds 1 6 Nm 2 2 Nm Attach the ignition module use the proper air gap gauge between the flywheel magnets and the module laminations use
70. r the 800 801 and 820 transaxles 696250 An in depth look at the manual transaxle MST Series This film will help you understand correct disassembly repair and reassembly procedures SPECIAL BOOKLETS INSTRUCTIONAL GUIDE 692738 Assists in the use and understanding of the Tecumseh Master Parts Manual Illustrates time saving features incorporated into the manual 4 CYCLE ENGINE FAILURE ANALYSIS 695590 This booklet is designed as a tool for the average technician to correctly assess the cause of failure CARBURETOR IDENTIFICATION TROUBLESHOOTING AND SERVICE BOOKLET 695907 This booklet is designed as a quick reference to carburetion problems and related repair procedures IGNITION SYSTEMS TROUBLESHOOTING BOOKLET 694903 This booklet contains information on the identification possible problems and related repair procedures of Tecumseh Ignition Systems SERVICE TOOLS BOOKLET 694862 This booklet depicts all specialty tools offered by Tecumseh which can be used on 2 and 4 cycle engines and Peerless units QUICK REFERENCE CHART BOOKLET 695933 This booklet contains the quick reference information found on Tecumseh wall charts This booklet is designed to be used as a work bench quick reference guide when servicing Tecumseh engines and motion drive systems 51 TOOLS FLYWHEEL PULLER 670299 STRAP WRENCH 670305 HEAVY GAUGE WIRE HOOK FOR REMOVING MUFFLER SPRINGS 12 LONG 309 mm PISTON AND RO
71. rk under Troubleshooting WA YES WET DRY Check If Spark Plug Is Wet or Dry Check Compression Release Defective Spark Plug for Stuck Open Condition rer Check Fuel Supply Restricted Air Filter and Fuel Cap Vent Restriction in Fuel System Improper or Stale Fuel filter screen Carburetion Problems Due to Flooding Over Priming etc Carburetion Problem Ignition System Blockage in Pulse Channel to Carburetor Plugged Muffler or Exhaust Port Poor Compression 16 TROUBLESHOOTING CARBURETION TC TM SERIES ADJUSTMENTS Low High FUEL SYSTEM Plugged Tank Filter or Vent Restricted Fuel Line Dirt in Fuel Passage Loose Damaged Fuel Line Leak in Pulse System Restricted Pulse Channel Loose Pump Cover Screws Defective Pump Diaphragm AIR SYSTEM Plugged Air Filter Defective Manifold Gasket Loose Carburetor Mounting Bolts Worn Throttle Shaft or Valve Incorrect Throttle Assembly Loose Throttle Valve Screw Throttle Shaft Too Tight Bent Throttle Linkage Defective Throttle Spring Bent Throttle Stop Lever Choke Not Functioning Properly Worn Choke Shaft or Valve Ne E Toes Ne dos 9 lt BN EN 17 TROUBLESHOOTING CARBURETION TC TM SERIES CONTINUED METERING SYSTEM LEVER Worn Lever Set Too High Set Too Low Not Free SPRING Distorted Improperly Installed DIAPHRAGM Leaking Air Fuel Worn Button Improper Asse
72. self locking nut and washer on the blower housing stud and remove the fuel tank 6 Remove the rewind starter assembly by removing three machine screws diag 7 5 Remove the rubber plugs 7 Remove the ignition grounding lead off the ignition module and remove the ignition module using a 1 4 Nr socket or Torx T15 drive gt 8 Use the strap wrench 670305 to hold the Te flywheel and loosen the flywheel nut until it is flush A Pp T with the end of the crankshaft 1 AA 5 9 Use flywheel puller part 670299 to pop the flywheel off the crankshaft taper unthread and remove the puller Remove the flywheel nut washer flywheel and flywheel key diag 7 6 NOTE DO NOT use a knock off tool on the crankshaft when removing the flywheel Permanent engine damage may result 10 Mark or note the location of the throttle link governor spring hook up and speed control to aid in assembly Remove the carburetor spacer gaskets and air baffle if equipped using a 1 4 socket on the carburetor studs 11 Remove the blower housing base by removing the three 5 16 hex head screws diag 7 7 12 Attach the engine tool holder part 670300 to the crankcase using the three removed blower housing base hex head screws Place tool in a bench vise diag 7 8 ai 13 On Type Il engines remove the muffler using 12 304 mm piece of heavy gauge wire with a 1
73. tance is felt due to compression pressure then stop Slowly release starter tension to prevent the engine from reversing due to compression pressure Remove the spark plug squirt 1 2 ounce 15 ml of clean 2 cycle engine oil into the spark plug hole Cover the spark plug hole with a shop towel and crank the engine over slowly several times Replace the spark plug and tighten see step 6 under Tune Up Procedure for proper spark plug torque Pull the starter handle as performed in step 1 The piston position blocks the cylinder ports preventing atmospheric air from entering and oil from leaving the cylinder bore during storage Replace the spark plug wire on the spark plug CHAPTER 2 AIR CLEANERS GENERAL INFORMATION The air cleaner is designed to eliminate dust and dirt from the air supply Most models of 2 cycle and 4 cycle engines use an air cleaner except engines that run in clean environments like snow throwers or ice augers On these applications a filter is not necessary and could collect snow or moisture and prevent proper engine operation On most applications filtered air is necessary to assure abrasive particles are removed before entering the combustion chamber Dirt allowed into the engine will quickly wear the internal components and shorten the life of the engine Tecumseh engines use either a polyurethane or a paper type air filter system A polyurethane pre filter or a flocked screen may be used in conjunction with the
74. ug The welch plug s must be flattened by taps with a small hammer on the installing punch Sealant such as fingernail polish is recommended to apply to an installed welch plug Use sparingly and wipe off excess immediately diag 3 13 Install the inlet needle spring metering lever and pin The metering lever hooks on the inlet needle and rests on the metering spring Install as an assembly and install the retaining screw diag 3 14 Check the metering lever tip height using a metering lever gauge part 670325 The tip height should be 060 to 070 1 52 mm to 1 77 mm from the face of the carburetor body on Walbro carburetors On Tecumseh and Tillotson carburetors the tip of the metering lever should be flush with surface of the carburetor body Install the idle mixture screw and spring and back the screw out from the closed position 1 1 1 8 turns for Walbro 1 1 4 1 3 8 turns for Tillotson carburetors Install the metering diaphragm cover gasket and cover Place the cover gasket over the locator pins on Walbro only on the carburetor body add the metering diaphragm with the long rivet head toward the carburetor body on top of the gasket add the cover and fasten the four screws diag 3 15 NOTE Do not re use old choke or throttle plate shutter screws New screws are treated with a dry Loctite adhesive to secure them in place 8 Install the pump gasket over the locator pins on the pump cove
75. ulse transformer trigger coil high tension lead and a spark plug Some TC Type II modules also contain an ignition rev limiting device to prevent the engine from exceeding the maximum rpm This type of limiter is used on mini carts for safety reasons All components except the spark plug and high tension lead are located in an encapsulated ignition module The module is protected by epoxy filler from exposure to dirt and moisture This system requires no maintenance other than checks of the high tension lead and spark plug OPERATION As the magnet in the flywheel rotates past the charge coil electrical energy is produced in the module The energy is stored in the capacitor approx 200 volts until it is released by an electrical switch SCR As the magnet continues to rotate it passes past a trigger coil where a low voltage signal is produced This low voltage signal closes the SCR switch allowing the energy stored in the capacitor to flow to a transformer where the voltage is increased from 200 volts to 25 000 volts This voltage flows along the high tension lead to the spark plug where it arcs across the electrodes and ignites the air fuel mixture diag 6 1 COMPONENTS FLYWHEEL WITH MAGNETS FLYWHEEL KEY IGNITION MODULE SPARK PLUG IGNITION SWITCH 30 IGNITION TROUBLESHOOTING Engine Will Not Start Engine Runs Erratically
76. ure acts only on the primary idle fuel discharge port due to throttle plate position A relatively small quantity of fuel is needed to operate the engine diag 3 3 During INTERMEDIATE throttle operation the secondary idle fuel discharge port supplies fuel after it is uncovered by the throttle plate As the throttle plate opens progressively further engine speed increases The velocity of air going through the carburetor venturi creates a low pressure area to develop at the main fuel discharge port while diminishing the effect of the low pressure area on the engine side of the throttle plate When the pressure at the venturi throat is less than that existing within the fuel chamber fuel is forced through the high speed mixture orifice and out the main fuel discharge port diag 3 4 At HIGH SPEED operation the throttle shutter is in a full open position The air velocity through the venturi increases which further lowers the air pressure at the main fuel discharge port All discharge ports are supplying fuel as the adjustment orifices will allow diag 3 5 The fuel pump diaphragm in the carburetor moves up and down by pressure changes pulsations caused by piston movement The pulsations are transferred to the pump by a passage called the impulse channel The pump diaphragm moves up drawing fuel into the pump fuel chamber during a positive pulse and a negative pulse moves the diaphragm down forcing fuel out of the fuel chamber throug
77. ut service procedures covered in this handbook You would like to order service tools You would like to request additional printed copies of this handbook You may find your Authorized Tecumseh Servicing Dealer on our website at www TecumsehPower com or call Tecumseh Power Company at 1 800 558 5402 or 262 377 2700 if you are located outside the U S or Canada Copyright 2005 Tecumseh Power Company All Rights Reserved CONTENTS CHAPTER 1 GENERAL 1 GENERAL SAFETY PREGAUTIONS elle 1 ENGINE IDENTIFICATION 2 een Suse ta era tte er 3 Olle ade eae 5 Em 6 TUNE UP FROCEDURE eee STORAGE neta C E M m 8 CHAPTER 2 AIR CLEANERS 2222 9 2 ee een ent 9 OPERATION ee ea era iin 9 TROUBLE SHOOTIN G rss 9 SERVICE DE 9 PAPER FILTER REMOVAL AND 10 POLYURETHANE FILTER REMOVAL AND 10 CHAPTER CARBURE
78. w it to reach normal operating temperature after 3 5 minutes As the speed control is set at the idle position turn the idle mixture screw slowly clockwise until the engine R P M just starts to decrease Stop and note this screw position Turn the idle mixture screw slowly counterclockwise The engine will increase R P M Continue to slowly turn the screw until the engine R P M starts to decrease Note this position and turn the mixture screw back clockwise halfway between the two engine R P M drop off positions The idle mixture adjustment is complete 19 CARBURETOR DISASSEMBLY 1 Note or mark the location and sequence of the diaphragm s gasket s and the metering or pump cover Remove the screw s gaskets and diaphragms Remove the idle mixture screw On Tillotson model HU carburetors remove the plastic screw or brass plug over the main mixture jet and remove the main mixture jet if necessary for cleaning diag 3 11 Use a 8 32 tap with the tapered flutes removed to turn into the brass welch plug until it bottoms and begins to turn the welch plug Carefully pull the welch plug from the carburetor body Note or mark the location and action of the throttle and air vane and choke shaft if applicable Remove the screw holding the throttle or choke shutter to the shaft Remove the Torx T8 screw use part 670334 holding the air vane to the throttle shaft if applicable Remove the clip screw dust seal ret

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