Tecumseh TC/TCH200/300 Series 2 Cycle Engines Service Manual

TC SERIES 2- Cycle T E C H N I C I A N ' S H A N D B O O K TECUMSEH This manual covers all TC, TCH 200 & 300 models. Downloaded from www.Manualslib.com manuals search engine

CONTENTS CHAPTER 1 GENERAL INFORMATION.............................................................................. 1 ENGINE IDENTIFICATION ......................................................................................................................1 OIL REQUIREMENTS ..............................................................................................................................1 FUEL REQUIREMENTS ..........................................................................................................................2 STORAGE ................................................................................................................................................3 CHAPTER 2 AIR CLEANERS ............................................................................................. 4 GENERAL INFORMATION ......................................................................................................................4 OPERATION.............................................................................................................................................4 TROUBLESHOOTING .............................................................................................................................4 SERVICE ..................................................................................................................................................4 PAPER FILTER REMOVAL AND REPLACEMENT .................................................................................5 POLYURETHANE FILTER REMOVAL AND SERVICE ...........................................................................5 CHAPTER 3 CARBURETORS AND FUEL SYSTEMS....................................................... 6 GENERAL INFORMATION ......................................................................................................................6 OPERATION.............................................................................................................................................6 FUEL PRIMERS .......................................................................................................................................7 COMPONENTS ........................................................................................................................................7 TILLOTSON CARBURETOR ...................................................................................................................8 TROUBLESHOOTING .............................................................................................................................9 TROUBLESHOOTING CARBURETION - TC SERIES.....................................................................10-11 TESTING ................................................................................................................................................12 SERVICE ................................................................................................................................................ 12 CARBURETOR PRE-SET AND ADJUSTMENT....................................................................................12 FUEL TANK SERVICE ........................................................................................................................... 13 CARBURETOR DISASSEMBLY ............................................................................................................ 13 CARBURETOR INSPECTION ...............................................................................................................14 CARBURETOR ASSEMBLY ............................................................................................................ 14-15 CHAPTER 4 GOVERNORS AND LINKAGE..................................................................... 16 GENERAL INFORMATION ....................................................................................................................16 OPERATION...........................................................................................................................................16 COMPONENTS ......................................................................................................................................16 TROUBLESHOOTING ...........................................................................................................................17 ENGINE OVERSPEEDING ....................................................................................................................17 ENGINE SURGING ................................................................................................................................17 SERVICE ................................................................................................................................................ 17 GOVERNOR ADJUSTMENT ........................................................................................................... 17-18 CHAPTER 5 REWIND STARTERS.................................................................................... 19 GENERAL INFORMATION ....................................................................................................................19 C Tecumseh Products Company 1998 Downloaded from www.Manualslib.com manuals search engine

CHAPTER 6 IGNITION ....................................................................................................... 21 GENERAL INFORMATION ....................................................................................................................21 OPERATION...........................................................................................................................................21 COMPONENTS ......................................................................................................................................21 TROUBLESHOOTING ...........................................................................................................................22 TESTING ................................................................................................................................................23 SERVICE ................................................................................................................................................ 23 AIR GAP SETTING ................................................................................................................................23 SPARK PLUG SERVICE ........................................................................................................................ 23 CHAPTER 7 INTERNAL ENGINE AND CYLINDER......................................................... 24 GENERAL INFORMATION ....................................................................................................................24 OPERATION...........................................................................................................................................24 COMPONENTS ......................................................................................................................................24 TROUBLESHOOTING ..................................................................................................................... 25-26 TESTING ................................................................................................................................................27 ENGINE KNOCKS..................................................................................................................................27 ENGINE OVERHEATS ...........................................................................................................................27 SURGES OR RUNS UNEVENLY .......................................................................................................... 27 MISFIRES............................................................................................................................................... 27 ENGINE VIBRATES EXCESSIVELY ..................................................................................................... 28 LACKS POWER ..................................................................................................................................... 28 SERVICE ................................................................................................................................................ 28 GENERAL INFORMATION ....................................................................................................................28 DISASSEMBLY PROCEDURE ........................................................................................................ 28-29 BEARING AND SEAL SERVICE............................................................................................................ 30 ASSEMBLY....................................................................................................................................... 31-33 CHAPTER 8 ENGINE SPECIFICATION AND SEARS CRAFTSMAN CROSS-REFERENCE ............................................................................................... 34 TC TORQUE SPECIFICATIONS............................................................................................................34 Downloaded from www.Manualslib.com manuals search engine

CHAPTER 1 GENERAL INFORMATION ENGINE IDENTIFICATION 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 (diag. 1-1). Identification Decal TC TYPE I ENGINE TC TYPE II ENGINE SHORT BLOCK IDENTIFICATION TAG SBV or SBH Identification number SER 4201 SBV1543 1-1 1-3 Model Number Identification Decal The engine identification decal will include the model number, specification number, warranty code, and date of manufacture (diag. 1-2). The model number designation following TC (Tecumseh Compact) indicate the cubic inch displacement of the engine. TC 300 indicates a 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 year in the decade (1995). The next three digits (114) indicate the Julian build date (114 th day 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) (diag. 1-3). TC300 3133C (B) 5114G CAUTION: THIS SYMBOL POINTS OUT IMPORTANT SAFETY INSTRUCTIONS WHICH IF NOT FOLLOWED COULD ENDANGER THE PERSONAL SAFETY OF YOURSELF AND OTHERS. FOLLOW ALL INSTRUCTIONS. OIL REQUIREMENTS TECUMSEH RECOMMENDS USING TWO CYCLE OIL PART #730227, which is a premium blend that ensures cylinder wall lubrication, mixes easy, does not separate and is specially formulated for use in air or water cooled two cycle engines. 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 owners operating instructions and on the decal attached to the blower housing or fuel tank of the engine. Serial Number or DOM 1-2 Date of Manufacture or Serial Number Warranty Code Specification Number 1 Downloaded from www.Manualslib.com manuals search engine

2 24:1 FUEL MIXTURE CHART ALL TC ENGINES NOTE: DO NOT MIX FUEL IN ENGINE OR EQUIPMENT FUEL TANK. U.S. METRIC Gas Oil To Be Added Petrol Oil To Be Added 1/2 Gal. 3.00 oz. 2 Liters 83 ml. 1 Gal. 6.00 oz. 4 Liters 167 ml. 2 Gal. 11.00 oz. 8 Liters 333 ml. MIXING OIL AND GASOLINE PROCEDURE 1. Fill approved, clean container one quarter full with the recommended gasoline. 2. Add the recommended amount of oil to the gasoline. 3. Secure the cap on the container and shake the container vigorously. 4. Remove the cap, add the remainder of the gasoline, secure the cap, re-mix. The fuel is ready to use. FUEL REQUIREMENTS Tecumseh Products 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, gasohol containing than 10% ethanol, unleaded regular gasoline containing more than 15% MTBE (Methyl Tertiary Butyl Ether), 15% ETBE (Ethyl Tertiary Butyl Ether) or 10% ethanol, gasoline additives, or white gas because engine/fuel system damage could result. See “STORAGE” instructions in Technician’s Manual, Operator’s Manual, or Bulletin 111. For year round fuel stability in and out of season, use Tecumseh's fuel stabilizer part number 730245. FUEL ADDITIVES Only fuel additives such as Tecumseh's fuel stabilizer part number 730245 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. CAUTION: 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. 4. Replace the blower housing and check all remote linkage for proper adjustment and operation. 5. 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 Technician's 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. 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. 1-4 Downloaded from www.Manualslib.com manuals search engine

3 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 look up system. STORAGE (IF THE ENGINE IS TO BE UNUSED FOR 30 DAYS OR MORE.) CAUTION: NEVER STORE THE ENGINE WITH FUEL IN THE TANK INDOORS OR IN ENCLOSED, POORLY VENTILATED AREAS, WHERE FUEL FUMES MAY REACH AN OPEN FLAME, SPARK OR PILOT LIGHT AS ON A FURNACE, WATER HEATER, CLOTHES DRYER, OR OTHER GAS APPLIANCE. Gasoline can become unstable in less than 30 days and form deposits that can impede proper 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 asTecumseh part number 730245. 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. CAUTION: DRAIN THE FUEL INTO AN APPROVED CONTAINER OUTDOORS, AND AWAY FROM ANY OPEN FLAME OR COMBUSTIVE SOURCE. BE SURE THE ENGINE IS COOL. 2. 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 in 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 resistance is felt due to compression pressure, then stop. Slowly release starter tension to prevent the engine from reversing due to compression pressure. 2. Remove the spark plug, squirt 1/2 ounce (15 ml.) of clean 2-cycle engine oil into the spark plug hole. 3. Cover the spark plug hole with a shop towel and crank the engine over, slowly, several times. 4. Replace the spark plug and tighten (see step # 5 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, air from entering and oil from leaving the cylinder bore during storage. 5. Replace the spark plug wire on the spark plug. TUNE-UP PROCEDURE (continued) Downloaded from www.Manualslib.com manuals search engine

4 CHAPTER 2 AIR CLEANERS TROUBLESHOOTING If the engine's performance is unsatisfactory (needs 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. Re-try the engine after filter replacement or service. If the problem after filter service, see Chapter 7 under "Troubleshooting" for additional causes. SERVICE Cleaning and oiling the polyurethane element (diag. 2-1) is recommended every three (3) months or every 25 operating hours. If the engine is used in extremely dusty or dirty conditions, the filter may require service every three hours or as often as necessary to maintain proper engine performance. 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 extremely dusty conditions. Use only original factory recommended replacement filters. NOTE: DO NOT ATTEMPT TO CLEAN OR OIL PAPER FILTERS. Air Cleaner Screen Polyurethane Filter 2-1 2-2 Air Cleaner Collar Clamp Cover 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 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. Downloaded from www.Manualslib.com manuals search engine

5 Paper Filter Removal and Replacement 1. Remove the polyurethane pre-filter (if equipped) from the air filter. 2. Inspect the filter(s) for discoloration or 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. 3. Loosen the clamp and slide the clamp toward the air filter. (diag. 2-3) 4. Slide the air filter and clamp off the carburetor adapter. Discard the old filter and keep the clamp. 5. Apply a thin layer of silicon sealant to the outside of the air cleaner adapter. 6. Install the clamp on the new air filter, slide the filter assembly onto the carburetor adapter as far as it will go. 7. Slide the clamp as close to the carburetor as possible. Tighten the clamp securely. Polyurethane Filter Removal and Service Kleen Aire® Air Cleaner or TC Type II 1. Remove the cover by pulling outward on the tab (diag. 2-4). On the TC Type II style engine, loosen the two screws (diag. 2-5). 2. Remove screen A (if equipped), foam filter and screen B from the air cleaner body (diag. 2-4). On TC Type II engines, remove the flocked screen and the foam filter (diag. 2-5). 3. Inspect the flocked screen and foam filter for is present, service the element or screen using the following steps. 4. 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. 5. Wash the polyurethane filter or polyurethane pre-filter (used with paper air filters) in a detergent water solution and squeeze (don't twist) until all dirt is removed. 6. 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. 7. Saturate the polyurethane filter with engine oil and squeeze (don't twist) to distribute and remove excess oil. 2-3 Poly Pre-Filter Air Cleaner Hose Clamp Carburetor Carburetor Adapter Clamp 2-4 2-5 Screen A Screen B Lock Nut Washer Polyurethane Filter Air Cleaner Housing Poly Air-Cleaner Flocked Screen Air Cleaner Cover Cover Screw Fuel Tank Downloaded from www.Manualslib.com manuals search engine

6 CHAPTER 3 CARBURETORS AND FUEL SYSTEMS Intake Air Fuel Engine Vacuum Impulse Intake Air Fuel Engine Vacuum Impulse Intake Air Fuel Engine Vacuum Impulse 3-1 3-2 3-3 GENERAL INFORMATION TC engines almost exclusively use diaphragm-type carburetors to be able to run effectively at any operating angle. The diaphragm carburetors are produced by 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. An alternate method to find the correct carburetor part number on float type carburetors 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 or Microfiche Catalog, a cross reference chart will convert a carburetor manufacturing number to a Tecumseh part number. OPERATION In the "CHOKE" or "START" position, the choke shutter is closed, and the only air entering the engine flows through openings around the choke shutter. As the recoil assembly is operated to start the engine, downward piston travel creates a low pressure area in the engine cylinder above the piston. Higher pressure atmospheric air rushes into the engine 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. 3-1). At IDLE the throttle shutter is almost closed, the low pressure 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. 3-2). 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. 3-3). Idle Start Intermediate Downloaded from www.Manualslib.com manuals search engine

7 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. 3-4). 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 through the inlet needle into the metering chamber. FUEL PRIMERS Primers used on TC engines supply a solid fuel charge to the carburetor main nozzle (diag. 3-5). 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. COMPONENTS Intake Air Fuel Engine Vacuum Impulse 3-4 High Speed 3-5 3-6 1. Diaphragm Cover Screw 2. Metering Diaphragm Cover 3. Diaphragm 4. Diaphragm Gasket 5. Metering Lever 6. Metering Lever Screw 7. Metering Lever Pin 8. Metering Lever Spring 9. Inlet Valve Needle 10. Inlet Valve Seat 11. Welch Plug 12. Choke Shaft 13. Choke Shutter Screw 14. Choke Shutter 15. Idle Mixture Screw 16. Idle Speed Screw 8 11 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. Dust Seal 29. Dust Seal Washer 12 13 19 20 22 26 27 29 2 1 3 5 17 18 23 24 25 27 28 21 WALBRO CARBURETOR 7 6 10 16 4 14 15 9 Downloaded from www.Manualslib.com manuals search engine

Tecumseh TC/TCH200/300 Series 2 Cycle Engines Service Manual

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