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TECUMSEH - 2-CYCLE ENGINES

1. 17 FUELFITTING ae T7 INLET FUEL FITTING 2m on oen 17 CHOKE SHAFT E 17 THROTTLE LEVER 2 17 IDLE SPEED ADJUSTMENT SCREW 17 GOVERNORS AND LINKAGE 18 AIR VANE GOVEHNONRNS iiiter 18 OPERATION aan 18 LINKAGE INSTALLATION 18 REWIND STARTERS ELECTRIC STARTERS AND ALTERNATORS eere 20 REWIND STARTERS na 20 COMPONENTS ee 20 ROPE SERVICE une er 20 STYLIZED REWIND STARTER 21 VERTICAL PULL STARTER HORIZONTAL ENGAGEMENT TYPE 2a 22 STYLIZED REWIND STARTER WITH PLASTIC RETAINER aa een 23 VERTICAL PULL STARTER VERTICAL ENGAGEMENT TYPE notet 24 REWIND STARTER MOUNTED IN HOUSING 25 ELECTRIC STARTERS eere 26 DRIVE ASSEMBLY SERVICE sssssssesesseseeen 26 STARTER CHECKING AND SERVICE 27 CHECK FIELD 2 2 2 27 ARMATURE CHECK una 27 TROUBLESHOOTING STARTERS 27 ALTERNATORS nun 28 CHECKING THE SYSTEM nette 28 FLYWHEEL INSIDE EDGE BRAKE SYSTEM 29 INSIDE EDGE SYSTEM use 29 COMPONENT Since hene la ee 29 SERVICE an ya ee ie 29 CONTROL CABLE nt 30 Copyright 1994 by Tecumseh Products Company All rights reserved No part of this book may be reproduced or transmitted in any form or by any means electronic or mechanical including photocopying recording or by any information storage and retrieval system without permission in writi
2. 44 CYLINDERS REEDS amp COMPRESSION RELEASE se een 45 CYLINDER A HEAD SERVICE 45 GASKETS 28 d ee eee ee 45 REED VALVES utis Ein Res 45 AUTOMATIC COMPRESSION RELEASE DOUBLE REED TYPE eessen 45 AUTOMATIC COMPRESSION RELEASE SINGLE REED TYPE eese 45 CYLINDER EXHAUST PORTS 46 TROUBLESHOOTING eee 47 ENGINE FAILS TO START OR STARTS WITH DIFFICULTY eeeeeeennnmnnnn 47 ENGINE KNOCKS esse 47 ENGINE MISSES UNDER LOAD 48 ENGINE LACKS POWER sene 48 ENGINE OVERHEATS ee 48 ENGINE SURGES OR RUNS UNEVENLY 49 ENGINE VIBRATES EXCESSIVELY 49 SPECIFICATIONS eese 50 ENGINE TYPE NUMBER AND LETTER REFERENCGCE 5 ob es 50 SEARS CRAFTSMAN CROSS REFERENCE 51 TABLE OF SPECIFICATIONS 52 61 TABLE OF TORQUE LIMITS 62 EDUCATIONAL MATERIALS AND TOOLS 63 AVAILABLE TECHNICIAN S HANDBOOKS 63 AVAILABLE FOREIGN TECHNICIAN S HANDBOOKS eene 63 TOOL KIT 670195D ceeseeeese 64 TOOLS eterni LOT 65 This manual contains information on Tecumseh Engines built to comply with emission regulations As a technician it is unlawful to modify or cause a change in the origin
3. FELT SEAL PH THROTTLE SHAFT CHOKE STOP SPRING SHUTTER S P CD gt FUEL FITTING O RING SEAT AND CLIP INLET NEEDLE A SPRING CLIP SCREW BOWL NUT WASHER HIGH SPEED BOWL NUT DIAPHRAGM TYPE CARBURETOR THROTTLE LEVER AND SHAFT CHOKE LEVER SPRING 8 AND SHAFT WASHER amp FELT SEAL FUEL INLET THROTTLE SHUTTER 1 SHUTTER SCREWS IDLE ADJUSTMENT SCREW CHOKE ES SHUTTER SEAL w 7 Y T WASHER gt A X SPRING id ei LOW SPEED HIGH SPEED e ADJUSTMENT ADJUSTMENT SCREW SOREW O DIAPHRAGM gt DIAPHRAGM gt a GASKET 3 DIAPHRAGM Sr SHUTTER SCREW COVER amp DIAPHRAGM PRIMER FITTING 2 COVER SCREW GOVERNORS AND LINKAGE AIR VANE GOVERNORS All Tecumseh 2 cycle engines covered in this book are equipped with pneumatic air vane governors The governor s function is to maintain aR 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 inthe engine R P M cause the air vane to move The throttle is opened as the engine R P M drops and is closed as the engine load is removed 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 veloc
4. 6699 17 015 6699 17 015 6699 17 015 Main Brg Dia Crankshaft None None 076 003 076 003 076 003 076 End Play Ge 406 016 406 016 406 016 406 61 TABLE OF TORQUE LIMITS A OA ROUNDS NEWTON METERS Flywheel Nut 264 324 30 37 0 Connecting Rod Screws Aluminum Rods 40 50 Steel Rods 70 80 Spark Plug 192 264 21 5 30 Fuel Tank Screws 12 20 Blower Housing Mounting Screws O 100 Muffler Mounting Screws 0 100 0 8 8 3 External Screws to Laminations 3 5 4 5 Carburetor Mounting Nuts 60 75 Compliance Brake Bracket to Oyimder Lan 7 9 Air Filter or Carburetor Baffle Metal 30 40 3 5 4 5 Air Filter Plastic 18 25 2 83 9 9 5 3 2 3 Reed Plate Cover Plate 35 45 9 9 7 9 5 5 Torque specifications listed on this page should not be confused with the torque value observed on engines which have been run Torque relaxation occurs on all engines from thermal expansion and contraction The torque specifications take relaxation into account so a sufficient clamping force exists after an engine has been run 62 EDUCATIONAL MATERIALS AND TOOLS AVAILABLE TECHNICIAN S HANDBOOKS 692508 Covers the diagnosis and repair of Tecumseh 2 cycle engines Except the TC Engine and TVS840 692509 Covers the diagnosis and repair ofthe Tecumseh 4 cycle light medium frame engines 691462A Covers the diagnosis and repair of Tecumseh 4 cycle large frame engines 6912
5. STARTER HOUSING STARTER PULLEY J SPRING amp COVER DOG SPRING STARTER DOG DOG RETAINER ASSEMBLY 1 2 If replacing the starter rope see Step 8 Install a new recoil spring if necessary by pushing the new spring out of the holder into the pulley cavity while aligning the outside spring hook into the deep notch in the pulley Push the spring cover in until seated Apply a small amount of lithium grease to the inner bore of the center shaft Replace or check that both starter dogs are in the pulley pockets and that the dog springs are hooked on the outer surface of the dog 23 5 Pinch the two legs of the plastic retainer together and start into the center shaft hole 6 Rotate the retainer so the two tabs on the bottom of the part fit between the dog and pulley hub left side ofthe dog Push the retainer in until the leg prongs pop out of the center shaft 7 Turn the starter over and snap the locking tab between the retainer legs replace the top decal NOTE Referto Service Bulletin 122 for metal locking tab 8 Wind the starter pulley counterclockwise four or five turns to pre load the recoil spring and thread the rope through the starter housing eyelet Pull enough rope through to tie a temporary knot in the rope Reattach the starter handle to the rope using a left hand knot Untie the temporary knot and allow the rope to recoil VERTICAL PULL STARTER VERTICAL ENGAGEMENT TYPE DISASSEM
6. 6 The engine must be firmly mounted to the associated equipment On rotary lawnmowers make sure blade is properly balanced and correctly torqued See disassembly section for flywheel removal and air gap setting procedure 7 Make sure all remote linkage is properly adjusted for operation 8 Fill tank with the proper fuel oil mix Start the engine allow it to warm up 5 minutes then adjust carburetor and engine R P M according to Tecumseh s recommendations Snow King engines should be run in outdoor temperatures for engine adjustments NOTE Emissionized engines have non adjustable carburetors in compliance with CARB California Air Resource Board and U S EPA United States Environmental Protection Agency These engines can not be modified without specific authorization COMPRESSION RELEASE PASSAGE EXHAUST PORT CLEANING The exhaust ports should be cleaned after each seventy five 75 to one hundred 100 hours of use Before cleaning the ports place the piston in the Bottom Dead Center position Then clean the ports using a pointed 3 8 diameter wooden dowel or similar tool Be sure not to scratch the port area Also remember to remove all the loose carbon particles from the engine NOTE When cleaning the exhaust ports check and clean the compression release passage 2 CYCLE THEORY OF OPERATION Air cooled 2 cycle engines differ from 4 cycles by having one power stroke for every revolution of the e
7. 7500 19 05 7503 19 058 See Note A Crankshaft 003 None None None S 076 End Play 016 GR 406 NOTE 1 642 08 14A 14B B T D C 110 642 16D 19A 20A 21 22 B T D C 078 NOTE 2 642 24 26 29 B T D C 087 7498 NOTE A Needle Bearing 7503 53 TABLE ar Bore 2 093 53 162 2 093 53 162 2 093 53 162 2 093 53 162 2 093 53 162 2 094 53 188 2 094 53 188 2 094 53 188 2 094 53 188 2 094 53 188 1 500 a 1 750 44 45 1 750 44 45 1 750 44 45 1 410 35 814 Point Gap 018 See Note 4 2 286 See Note 2 E Note jS Spark Plug Gap BIFA Piston Ring e Ge pra Rs End Gap p p p ps Ku Piston 2 0870 58 01 2 0870 58 01 2 0870 53 01 2 0873 53 017 2 0870 53 01 Diameter 2 0880 53 035 2 0880 53 035 2 0880 53 035 2 0883 53 043 2 0880 53 035 Top 0655 1 664 0655 1 664 0665 1 689 0655 1 664 0655 1 664 Piston Ring 0665 1 689 0665 1 689 0975 2 477 0985 2 413 0665 1 689 Groove Width Ed 1 638 0645 1 638 0645 1 638 0955 2 426 ig ES Bot Ed 1 664 0655 1 664 0655 1 664 0965 2 451 1 ES Piston Ring 0615 1 562 0615 1 562 0615 1 562 0615 1 562 0625 1 587 Width 0625 1 587 0625 1 587 0625 1 587 0935 2 375 0925 2 349 Piston Pin 4997 12 692 4997 12 692 4997 12 692 4997 12 692 4997 12 692 Diameter 4999 12 697 4999 12 697 4999 12 697 4999 12 697 4999 12 697 Crank Pin Journal 8442 21 443 6857 12 417 8442 21 443 6857 17 417 5614 14
8. 9 64 3 572 mm diameter Part No 730526 100 30 48 meters spool 5 rope 5 32 3 964 mm diameter Part No 730514 100 30 48 meters spool 6 rope 3 16 4 762 mm diameter Part No 730516 100 30 48 meters spool Standard rope lengths 54 16 5 meters standard stamped steel starter 61 18 6 meters vertical pull horizontal engagement type vertical pull vertical engagement type extended handlebar rope start compliance 65 20 meters 85 26 meters Check the old rope for the right length for the application Some applications require longer lengths The rope ends should be cauterized by burning with a match and wiping the rope end with a cloth while hot Rope replacement can be done without the starter being disassembled on vertical pull starters that have V notches in the bracket Use the following procedure for rope replacement 1 Remove the starter assembly from the engine 2 Turn the pulley until the staple in the pulley lines up with the V notch Pry out the staple with a small screwdriver and remove the original rope 3 Turn the pulley counterclockwise to fully wind the starter return spring until tight Allow the pulley to unwind until the hole in the pulley lines up with the V notch 4 Hold the pulley in this position and feed the new rope through the hole and tie a left handed knot on the rope end Make sure the rope and knot do not protrude from the knot cavity
9. FROM THE 6 O CLOCK POSITION THE ROD WILL TURN ABOUT 1 2 TURN EACH WAY BEFORE BEING STOPPED BY THE SPRING ROD CARBURETOR ADJUSTMENTS Emission grade carburetors will have fixed main and idle circuits The absence of adjustment screws indicate fixed jets with no adjustments necessary CARBURETOR ADJUSTMENTS IDLE SPEED ADJUSTMENT This screw is located on top of the carburetor and contacts the throttle To pre set the idle speed back out the screw then turn in until the screw just touches the throttle lever Finally turn the screw in one 1 turn Once the engine is running and brought up to operating temperature 3 5 minutes the final idle R P M can be adjusted with the aid of a tachometer FLOAT TYPE FIXED MAIN IDLE ADJUST Turn the mixture adjusting screw in clockwise finger tight then one 1 turn out counterclockwise This setting is approximate and will be enough to allow the engine to start so that final carburetor adjustments can be made Start the engine and allow it to warm up for approximately 5 minutes Do not adjust the carburetor with the engine cold NOTE If the engine falters or stops after the choke lever is moved to the OFF position open the mixture adjusting screw 1 4 turn counterclockwise and restart the engine With the engine running place the speed control in the slow position Turn the mixture adjusting screw clockwise until the engine starts to falter remember this location Next
10. IDLE Remove welch plug and blow air INTERMEDIATE through air passages AND AIR BLEED ORIFICES INLET SEAT Remove and replace GASKET 22 NAS IDLE MIXTURE ADJUSTMENT Se Cy NS grs ao SCREW AND O RAR INLET NEEDLE RING If Presen q eer ei N as SEAT AND Proper installation of assembly is MAIN MIXTURE KEEN EEN SPRING important See appropriate chapter Sean ADJUSTMENT ASSEMBLY for procedures SCREW AND O RING If Present LZ DIAPHRAGM GASKET Gasket and diaphragm sequence may be reversed on some models DIAPHRAGM Head of rivet must touch inlet needle The check ball is a non serviceable item Clean with carburetor spray and low air pressure only MAIN NOZZLE WITH CHECK BALL Hole must be clean On models with ATMOSPHERIC VENT HOLE primer bulb vent hole is very small NON METALLIC ITEMS CAN BE DAMAGED ian Bb REIT BY HARSH CARBURETOR CLEANERS EMISSIONIZED DIAPHRAGM CARBURETION Loosen screw until it just clears throttle lever then turn screw in 1 turn IDLE SPEED ADJUSTMENT SCREW THROTTLE SHAFT LEVER AND RETURN SPRING THROTTLE SHUTTER Place detent reference mark to proper location See chapter appropriate to specific carburetor IDLE Remove welch plug and blow air INTERMEDIATE through air passages AND AIR BLEED ORIFICES TAMPER RESISTANT CAP Pie
11. MAGNETO END OF THE CRANKSHAFT NOTE If a knock off tool is used the pounding may cause the ball bearing to dislodge from the shroud base and force the lower thrust face of the crankshaft against the cylinder thrust face TO CORRECT THIS CONDITION RAP SHARPLY WITH RAWHIDE MALLET ON THE P T O END TO PROVIDE CLEARANCE BETWEEN CRANKSHAFT AND CYLINDER THRUST FACE BALL BEARING MUST HAVE CLEARANCE If the flywheel is difficult to remove from the crankshaft because of rust etc the use of a propane torch can be helpful Heat the area immediately outside of the crankshaft The aluminum alloy in the flywheel should expand enough to break the seal away from the steel crankshaft FLYWHEEL MAGNETS The magnets in the flywheel rarely lose their magnetic strength If magnets are suspected to be faulty place the flywheel upside down on a wooden surface Hold a screwdriver by the extreme end of handle with the point down Move the blade to within 3 4 inch of magnets The magnets should attract the screwdriver blade against the magnet SCREWDRIVER LENGTH APPROXIMATELY 6 15 24 cm MAGNETS FLYWHEEL KEYS The flywheel key locates the flywheel to the crankshaft in the proper position If a flywheel key is sheared or partially sheared the engine will not start or may be difficult to start LT L le STEEL ALUMINUM ALLOY 2 f CRANKSHAFT GOLD TIMING SOLID STATE TABS IGNITION NOTE Use the Tecumseh Master Parts
12. 0965 2 451 0655 1 664 0655 1 664 0655 1 664 Piston Ring 0615 1 562 0615 1 562 0625 1 587 0615 1 562 0615 1 562 Width 0625 1 587 0935 2 375 0925 2 35 0625 1 587 0625 1 587 Piston Pin 4997 12 692 3750 9 525 4997 12 692 3750 9 525 4997 12 692 Diameter 4999 12 697 3751 9 528 4999 12 698 3751 9 528 4999 12 697 Crank Pin Journal 6259 15 898 6957 17 671 6259 15 898 6857 17 417 6857 17 417 Diameter 6266 15 916 6865 17 427 6266 15 916 6868 17 445 6865 17 445 Crankshaft 8650 21 971 8745 22 12 6691 16 995 6691 16 995 9998 25 349 P T O Side 8850 22 479 8750 22 225 6695 17 001 6695 17 001 1 0003 25 408 Main Brg Dia Crankshaft 7495 19 037 7495 19 037 7495 19 037 7495 19 037 7495 19 037 Magneto Side 7503 19 058 7500 19 058 7500 19 058 7500 19 058 7500 19 058 Main Brg Dia Crankshaft None None 003 076 None None None None None None End Play 016 406 55 Reference BT Bore 2 093 53 162 2 093 53 162 2 093 53 162 2 4375 61 913 2 437 61 900 2 094 53 188 2 094 53 188 2 094 53 188 2 4385 61 938 2 438 61 925 1 750 44 45 1 410 35 814 1 250 31 75 1 750 44 45 1 750 44 45 Point Gap mr EM ms EN EF d Spark Plug Gap Piston Ring ie P Ge us M End Gap m n n Pu p Piston 2 0870 53 01 2 0870 53 01 2 0870 53 01 2 4302 161 727 2 4302 61 727 Diameter 2 0880 53 035 2 0880 53 035 2 0880 53 035 2 4312 61 753 2 4312 61 753 Top 1 638 0645 1 638 0655
13. AND REWIND SPRING ASSY ra DOG SPRING STARTER DOG d 2 WASHER S RETAINER 8 BRAKE SPRING WASHER SPRING PIN 21 ASSEMBLY PROCEDURE NOTE It is critical to support the starter on a deep well socket to prevent damage 1 Reverse the disassembly procedure The starter dogs with the dog springs must snap back to the center of the pulley disengaged position When the rope is pulled the tabs on the retainer must be positioned so that they will force the starter dogs to engage the starter cup diag 7 amp 8 Always replace the center spring pin with a new one upon reassembly Place the two new plastic washers between the center leg of the starter and the retainer New plastic washers are provided with a new center spring pin Discard the old plastic washer Place the rewind on a flat surface and drive the new center pin in until it is within 1 8 3 175 mm of the top of the starter NOTE DO NOT DRIVE THE CENTER PIN IN TOO FAR 22 The retainer will bend and the starter dogs will not engage the starter cup On the stamped steel starter the center pin should be driven in until it contacts the shoulder in the starter body Wind the starter pulley counterclockwise four or five turns to pre load the recoil spring thread the rope through the starter housing eyelet and tie a temporary knot in the rope Reattach the starter handle to the rope using a left hand knot Untie the temp
14. Crankshaft Engines Craftsman No Column No 200 503111 16 200 583111 16 200 593121 16 200 602112 35 200 613111 16 200 633111 35 200 643121 35 200 672102 26 200 682102 26 200 692112 26 200 692122 26 200 692132 26 200 701001 AH600 1665N 200 711001 HSK600 1665P 200 731001 HSK600 1686R 200 731011 HSK600 1687R 143 943071 HSK600 1687S 143 953071 HSK600 1700S 143 973071 HSK600 1705S 143 973091 HSK600 1700S 143 983071 HSK600 1708T 143 993071 HSK600 1712T AAR oo 09 00 09 09 09 OO OO Y Y O O O O No o Reference Column Stroke Cu In Displacement in cc Point Gap Timing B T D C Spark Plug Gap Piston Ring End Gap Piston Diameter Top Piston Ring Groove Width Bot Piston Ring Width Piston Pin Diameter Crank Pin Journal Diameter Crankshaft P T O Side Main Brg Dia Crankshaft Magneto Side Main Brg Dia Crankshaft End Play 52 2 093 2 094 1 250 p 2 0870 2 0880 0655 0665 0645 0655 0615 0625 4997 4999 5611 5618 6691 6695 6691 6695 None TABLE OF SPECIFICATIONS Metric 53 162 2 093 53 188 2 094 31 75 1 410 017 SE 53 01 2 0870 53 035 2 0880 1 664 0655 1 689 0665 1 638 0645 1 664 0655 1 562 0615 1 587 0625 12 692 4997 12 697 4999 14 252 5614 14 270 5621 16 995 6691 17 005 6695 16 995 6691 17 005 6695 Metric 53 162 53 188 35 814 78 7 432 2 54 762 p 4
15. EXPANDER No 670117 Piston ring expander TAPER GAP GAUGE No 670156 Vibration tachometer No 670298 Aligning Pin
16. Manual to determine correct key for the application ADAPTER KEY TO FLYWHEEL ASSEMBLY When an adapter is used place the adapter with its raised key area in the flywheel keyway before putting the flywheel on the engine SLEEVE TO BE PRESSED IN FLUSH WITH HUB FLYWHEEL SLEEVE Some engines utilize a sleeve between the crankshaft and flywheel which acts as a flywheel key If this sleeve becomes sheared or damaged replace The flywheel sleeve is pressed into the crankshaft opening in the flywheel and should be flush or slightly below flush from the inside surface of flywheel before in stalling on crankshaft For engines equipped with brake system a new key and flywheel are shown Torque procedures are the same NON COMPLIANCE ENGINE COMPLIANCE ENGINE FLYWHEEL TORQUE Torque flywheel to the proper specification See the tables in specification section for the proper torque setting Loose lawn mower blades and adapters can contribute to sheared keys REPLACING MAGNETO BREAKER POINTS Remove the nut holding the electrical leads to the screw on the movable portion of the breaker points Remove the screw from the stationary breaker point and remove point set Reinstall the new breaker point set into position and adjust the point gap according to the specifications Points must be adjusted when the rubbing block of the points is on the highest spot on the breaker cam Clean points by putting lint free paper betwe
17. PATH OF MAGNET LINES OF FORCE PRIMARY WINDING POINTS CLOSED FLYWHEEL ROTATION As the flywheel continues to rotate the North Pole approaches the last leg of the lamination stack The magnetic field through the center leg reverses producing alarge change in the magnetic field and a high current in the primary windings of the coil Atthis time the contacts open and the primary current stops flowing This change in current causes a voltage in the primary windings which induces the high voltage in the secondary winding of the coil The voltage is routed through the spark plug wire to the spark plug and then jumps the gap of the plug to ignite the fuel air mixture POINTS OPEN 31 1985 to Present SOLID STATE IGNITION Tecumseh s solid state capacitor discharge ignition CDI is an all electronic ignition system and is encapsulated in epoxy for protection against dirt and moisture SOLID STATE IGNITION OPERATION As the magnets in the flywheel rotate past the charge coil electrical energy is produced in the module This energy is transferred to a capacitor where it is stored until it is needed to fire the spark plug The magnet continues rotating past atrigger coil where a low voltage signal is produced and closes an electronic switch SCR The energy which was stored in the capacitor is now transferred through the switch SCR to a transformer where the voltage is increased from 200 volts to 25 000 volts Th
18. _ GASKET e o LE C 2 ef a Use a socket to remove inlet needle and seat Replace with complete assembly FUEL INLET FITTING If necessary this fitting can IDLE MIXTURE SCREW be removed by pulling and twisting Be sure to install in the same position as the original When installing fitting insert tip into the carburetor body then coat the exposed portion of the shank with Loctite 242 Blue then press it in until the shoulder contacts the carburetor body THEN APPLY LOCTITE 242 BLUE Pressing the bulb creates air pressure against the diaphragm Fully depress primer bulb with your thumb making sure that the vent hole in bulb is covered Release and allow bulb to return to original position As the diaphragm lifts the inlet needle is lifted off its seat and the fuel within the reservoir is fed up through the passages into the air horn A one way valve in the body prevents the fuel from being forced back into the fuel tank CARBURETOR CHECK VALVE Diaphragm carburetors with primers must have a check valve located in or behind the fuel inlet fitting of the carburetor This is to prevent fuel from being forced back to the fuel line and tank when priming Two types of check valves have been used One is a brass check valve pushed into the carburetor body in the fuel inlet The other is a teflon disc located in the area under the fuel fitting These two types of check valves are not interchangeable To remove t
19. cable conduit screw with a screw other than a service part replacement be certain that the screw length is not too long as to prevent free travel ofthe lever Make sure the button on the starter interlock switch is completely depressed when the control is fully applied The cable must provide enough travel so the brake will contact the flywheel Some slack should exist in the cable adjustment to compensate for brake pad wear SCREW END MUST y NOT BLOCK LEVER ACTION e When installing a inside edge brake bracket assembly be sure the slotted holes in the brake bracket are all the way down on the fasteners This will properly align the brake bracket to the flywheel brake surface sr I pe y ALTIRO ER Pa E MOUNTING HOLES y MECHANISM FULL DOWN BEFORE SCREWS TORQUED IGNITION IGNITION OPERATION PRE 1985 Production MAGNETO IGNITION Tecumseh s magneto ignition consists of a stator assembly made up of a coil laminations contact points condenser and a permanent magnet mounted in the flywheel of the engine COIL The coil consists of a primary and a secondary winding of wire The primary is the low voltage 200 300 volts primary winding consists of about 150 turns of heavy gage wire next to the core One end of the primary is connected to the insulated contact point and the other end is grounded to the stator body The secondary winding consists of extremely fine wire with many turns about 10 000 wrapped
20. caused by extra air getting into the crankcase Engines could be equipped with either one piece oil seals or three pieces consisting of a seal retainer and retainer ring they are not interchangeable ONE PIECE SEALS An oil seal remover tool can be used for seal removal in some engines In some cases it may be necessary to disassemble engine to remove the oil seals Seal driver protectors are available for most one piece oil seals Select the proper tool from the tool list in Chapter 8 Place the oil seal over the driver protector place over crankshaft and drive into position using universal driver No 670272 DRIVER No 670272 OIL SEAL DRIVER PROTECTOR THREE PIECE SEALS To remove seals use a sharp object such as an ice pick to pry out the retainer spring then remove the retainer and seal In some cases it may be necessary to remove the crankshaft to remove the oil seals OUTBOARD SEAL SERVICE Oil seals on the power take off end of the crankshaft are installed in an inverted upside down position to keep water out of engine 44 CYLINDERS REEDS amp COMPRESSION RELEASE CYLINDER amp HEAD SERVICE Check cylinder for bore damage or scoring Check for broken or cracked fins warped head or head mounting surface If warped extensively more than 005 127 mm replace Always replace head gasket and torque to proper specification GASKETS Replace all gaskets in reassembly and make sure all sealing surfaces
21. in the socket closest to the rope hole in pulley 4 Replace brake spring brake and install E clip To put tension on spring wind pulley counterclockwise until tight then allow to unwind until the hole in the pulley lines up with the eyelet in housing then install rope and handle GUIDE BRAKE ENDS WHEN PIN IS REMOVED STRUT THROUGH SLOT WILL ROTATE 45 CLOCKWISE REWIND STARTER MOUNTED IN HOUSING DISASSEMBLY PROCEDURE 1 Pullrope outto untie knot in rope and slowly release spring tension 2 Remove E clip brake brake spring starter dog and return spring 3 Lift out pulley rewind spring is located in the housing Replace all worn or damaged parts 25 ELECTRIC STARTERS The following electric starter illustrations will not be identical in configuration to the starter being serviced but tests apply unless otherwise stated Starters labeled CSA cannot be serviced except for external components y Me WASHER Za S S e RETAINER RING N god gt a a lt OF Eee a ae N ENGAGING NUT SPRING ARMATURE GEAR DRIVE ASSEMBLY SERVICE Pinion gear parts should be checked for damage or wear If the gear sticks on the shaft it should be washed in solvent to remove dirt and grease then dried thoroughly If damaged replace with new parts On units with the gear under the cap assembly use the following procedure for disassembly 1 Remove retainer ring from armature shaft 2 Remove the
22. laying on a flat surface If warped replace If not warped severely it can be refaced using a hard surface and emery cloth Notches on the carburetor body insure that the gasket valve and cover are positioned on the body correctly When tightening screws snug bottom Screw then top screw and torque to 6 8 in Ibs OUTBOARD CONTROL PANEL Install the idle ment rod into the bracket then turn the setscrew STRAINER OUTLET FLAP into the rod a complete 2 turns Then position the extended end ofthe choke rod spring on the idle adjustment rod and align the spring with the choke rod holes in the bracket Press the choke rod through the bracket and spring with the link attaching hole toward the carburetor side Install the choke shaft link in the rod then install the other end in the choke lever Install the control bracket to the carburetor but do not tighten screw completely Tighten the setscrew to secure the rod to the idle CHOKE ROD THROTTLE ROD STOP LEVER POST IDLE ADJUST NEEDLE AND SPRING adjustment cable The rod should turn about a half turn before contacting the extended end of the choke spring It is important that the idle adjustment screw be one full turn from closed and that the rod setscrew be down 6 o clock position when connecting the rod and coil Tighten the control bracket screw Pull the choke rod to assure that the choke shutter closes ABOUT 1 2 TURN 6 O CLOCK POSITION
23. of plastic dip the end of the screw in oil before installation to prevent damage FUEL BOWL RETAINING NUT The fuel bowl retaining nut has a fixed main jet incorporated in the nut This small jet must be clean for proper fuel metering Clean by using compressed air DO NOT USE WIRE OR HARD OBJECTS FOR CLEANING CARBURETOR VENTING Float type carburetors must have atmospheric air pressure acting against the fuel in the fuel bowl These vents can be external with a hole drilled through the side of the carburetor casting or internal where atmospheric air is picked up in the air horn near the air cleaner Regardless of the type these vents must be clear and free from dirt paint grease etc HIGH TILT FLOAT STYLE carburetors use an external main air bleed MAIN AIR BLEED FUEL BOWL The fuel bowl must be free of dirt and corrosion When disassembling a carburetor for repair always replace the fuel bowl O ring Lubricate the O ring with a small amount of oil for easier installation Install the float bowl by placing the detent portion opposite of the hinge pin Make sure the deepest end of the bowl is opposite of the inlet needle The bowl has a small dimple located in the deepest part The purpose of this dimple is to minimize the chances of the float sticking to the bottom of the bowl caused by stale fuel DETENT FLOAT Remove the float by pulling out the float hinge pin Lift the float away fro
24. out all passages with compressed air in the opposite direction of normal fuel flow The carburetor body on non emission carburetors contains a main nozzle tube pressed into the carburetor body to a predetermined depth within the venturi of the carburetor DO NOT attempt to remove this main nozzle Any movement of this nozzle will seriously affect the metering characteristics of the carburetor Emissions carburetors have a serviceable plastic nozzle Clean the well surrounding the main nozzle with carburetor 10 MAIN NOZZLE DO NOT ATTEMPT TO REMOVE cleaner and compressed air With the choke plate and shaft removed blow compressed air through the high speed air bleed located just behind the lower choke shaft bearing and immediately in front of the venturi to remove any dirt that may have accumulated Blow compressed airthrough all ofthe passages making sure they are free of dirt varnish or foreign material DIAPHRAGMS Inspect diaphragms for cracks tears or brittleness Replace if necessary Rivet head on diaphragm must always face toward the inlet needle valve If the carburetor has an F designation on the casting it will identify the installation sequence of the gasket and diaphragm on the carburetor F designated carburetors have the diaphragm installed first then the gasket then the cover If there is no designation the sequence is gasket diaphragm and cover e a gt RIDGE AND RIVET HEAD UP gt
25. reed valve through a port into the piston pin and out the exhaust port PISTON EXHAUST PORT NN A N A N y N P aN N N LA pZ PISTON TYPE Il PIN As the engine starts and compression increases the reed will be forced against the bottom port sealing it and the engine will run under full compression PISTON SINGLE REED CLOSED TYPE Il Installthe reed cover single reed type with the small hole towards the spark plug 45 The piston used in the single reed compression release system has a cutout at the piston pin hole The piston must be installed with the cut out located on the side facing the compression release CYLINDER EXHAUST PORTS The muffler and cylinder exhaust ports should be cleaned after each seventy five 75 to one hundred 100 hours of operation It is recommended that the cylinder head be removed and carbon cleaned from the ports cylinder head and top of piston CAUTION Do Not Scratch Metal Surfaces With the cylinder head removed remove any carbon deposits from the cylinder wall head and the top of the piston Using a pointed 3 8 wooden dowel or similar tool remove the carbon from the exhaust ports Being sure to remove all loose carbon particles from the engine NOTE When cleaning the exhaust ports check and clean the compression release passage 46 TROUBLESHOOTING 2 CYCLE ENGINE TROUBLESHOOTING CHART Cause R
26. step by step procedure for teardown and reassembly of the 900 910 and 920 series transaxles 695185 Electrical Troubleshooting This video training program will assist the small engine technician in the proper procedures for troubleshooting electrical systems on outdoor power equipment 695285 An in depth look atthe 800 series transaxles Detailing the teardown and reassembly procedures for the 800 801 and 820 transaxles SPECIALTY TROUBLESHOOTING BOOKLETS INSTRUCTIONAL GUIDE 692738 Assists in the use and understanding of the Tecumseh Master Parts Manual Illustrates time saving features incorporated into the manual Explains new carburetor parts breakdown format 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 TROUBLESHOOTING 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 SPECIAL 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 Th
27. the starter to crank unless the engine blade control is depressed Where a two motion control is used the interlock switch is utilized as the starter switch The Torsion Spring supplies the pressure to the brake lever and brake pad to stop the flywheel The Control Cable transfers the motion of the engine blade control to the brake system SERVICE If the brake system fails to kill the ignition and stop the blade within 3 seconds the following service procedures should be followed Remove the flywheel as outlined in IGNITION section NOTE BEFORE THE FLYWHEEL IS REMOVED OR REPLACED THE BRAKE PRESSURE ON THE FLYWHEEL MUST BE RE LEVELED AS OUTLINED 29 INSIDE EDGE To relieve the brake pressure on the flywheel compress the spring by moving the lever toward the spark plug when the hole in the lever aligns with the hole in the bracket secure the lever with alignment tool 670298 then remove the flywheel diag 7 Remove the alignment tool Release the spring tension by unhooking the short end of the spring from bracket with a pliers Remove the E clip from the brake pad shaft Slide the pad lever from the shaft and unhook the link Inspect the brake pad for dirt oil or grease contamination If the pad is contaminated or if there is less than 060 1 524 mm of brake pad material at the pad s thinnest point replacement is necessary The brake pad is bonded to the brake lever and must be replaced as an assembly
28. two nuts from the through bolts holding on the cap assembly 3 Slide off the cap assembly The engaging nut gear spring and spring retainer will remain in the cap assembly 4 Remove inspect and replace as necessary Use reverse procedure for assembly 26 The following starter number 590556 is a sealed UL and CSA approved starter and the only component that can be serviced is the drive assembly ENGAGING NUT N GEAR ANTI DRIFT SPRING SPRING RETAINER N RS b RETAINER RING DUST COVER To disassemble the drive assembly use the following procedure 1 Remove plastic dust cover 2 Push down spring retainer and remove retainer ring 3 Slide off spring retainer anti drift spring gear friction washer and engaging nut Inspect and replace as necessary Use reverse procedure for assembly TORX E8 HEAD SCREW The 590556 Electric Starter uses a mounting screw with a Torx E 8 head To torque this screw you must use a 670307 Torx E 8 socket STARTER CHECKING AND SERVICE Remove nuts at both ends of the starter and take off rear end cap CHECK BRUSHES Before removing the armature check brushes for wear Make sure brushes are not worn to the point where the brush wire bottoms out in the slot of the brush holder Brush springs must have enough strength to keep tension on the brushes and hold them against the commutator If brushes need replacement remove by unhooking the termi
29. 0 8113 20 607 6922 17 582 8445 21 450 Diameter 8118 20 620 8450 21 463 8118 20 620 6927 17 595 8450 21 463 Crankshaft 9998 25 395 9993 25 295 7498 19 045 6695 17 005 9998 25 395 P T O Side 1 0003 25 408 1 0003 25 408 7503 19 058 6699 17 015 1 0003 25 408 Main Brg Dia Crankshaft 6695 17 005 6695 17 005 6695 17 005 8748 22 22 6695 17 005 Magneto Side 6699 17 015 6699 17 015 6699 17 015 8753 22 233 6699 17 015 Main Brg Dia Crankshaft 003 076 003 076 None None None None 003 076 End Play 016 406 016 406 016 406 59 TABLE OF SPECIFICATIONS perenes e J s 7 Bore 2 093 53 162 2 093 53 162 2 093 53 162 2 093 53 162 2 093 53 162 2 094 53 188 2 094 53 188 2 094 53 188 2 094 53 188 2 094 53 188 1 828 46 431 1 500 En 1 828 46 431 1 746 44 348 1 500 ES Point Gap AA RETE Ext Ext 088 2 235 070 1 778 Ext Ext Ext Ext T D C Ignition Ignition Ignition Ignition Ignition Ignition Spark Plug Gap Piston Ring 006 152 006 152 006 152 006 152 006 152 End Gap 016 406 016 406 016 406 016 406 016 406 Piston 2 0880 53 035 2 0880 53 035 2 0880 53 035 2 0880 53 035 2 0880 53 035 Diameter 2 0885 53 049 2 0885 53 049 2 0885 53 049 2 0885 53 049 2 0885 53 049 Top 0655 1 664 0655 1 664 0655 1 664 0655 1 664 0655 1 664 Piston Ring 0665 1 689 0665 1 689 0665 1 689 0665 1 689 0665 1 689 Groove Width 0645 1 638 0645 1
30. 03 Diameter 2 0885 53 049 2 0882 53 04 2 0882 53 04 2 0882 53 04 2 0882 53 04 2 0882 53 04 Top 1 664 0655 1 664 0655 1 664 0655 1 664 0655 1 664 0655 1 664 Piston Ring 1 689 0665 1 689 0665 1 689 0665 1 689 0665 1 689 0665 1 689 Groove Width 1 638 0655 1 664 0655 1 664 0655 1 664 0655 1 664 0655 1 664 Bot 1 664 0665 1 689 0665 1 689 0665 1 689 0665 1 689 0665 1 689 Piston Ring 0615 1 562 0615 1 562 0615 1 562 0615 1 562 0615 1 562 0615 1 562 Width 0625 1 587 0625 1 587 0625 1 587 0625 1 587 0625 1 587 0625 1 587 Piston Pin 4997 12 692 5005 12 713 5005 12 713 5005 12 713 5005 12 713 5005 12 713 Diameter 4999 12 697 5007 12 718 5007 12 718 5007 12 718 5007 12 718 5007 12 718 Crank Pin Journal 6922 17 582 8445 21 450 8445 21 450 8445 21 450 8445 21 450 8445 21 450 Diameter 6927 17 595 8450 21 463 8450 21 463 8450 21 463 8450 21 463 8450 21 463 Crankshaft 7498 19 045 9998 25 395 9998 25 395 7498 19 045 7498 19 045 9998 25 395 P T O Side 7503 19 058 1 0003 25 408 1 0003 25 408 7503 19 058 7503 19 058 1 0003 25 408 Main Brg Dia Crankshaft 6695 17 005 6695 17 005 6695 17 005 6695 17 005 6695 17 005 6695 17 005 Magneto Side 6699 17 015 6699 17 015 6699 17 015
31. 1 664 0655 1 664 0655 1 664 Piston Ring 1 664 0655 1 664 0665 1 689 0665 1 689 0665 1 689 Groove Width 1 638 0645 1 638 0645 1 638 0645 1 638 0645 1 638 Bot 1 664 0655 1 664 0655 1 664 0655 1 664 0655 1 664 Piston Ring 1 562 0615 1 562 0615 1 562 0615 1 562 0615 1 562 Width 1 587 0625 1 587 0625 1 587 0625 1 587 0625 1 587 Piston Pin 12 692 4997 12 692 4997 12 692 4997 12 692 4997 12 692 Diameter 12 675 4999 12 675 4999 12 675 4999 12 675 4999 12 675 Crank Pin Journal 21 443 5614 14 26 5611 14 252 6259 15 898 6919 17 574 Diameter 21 463 5621 14 277 5618 14 270 6266 15 916 6927 17 595 Crankshaft 16 995 6691 16 995 6691 16 995 6691 16 995 6691 16 995 P T O Side 17 005 6695 17 005 6695 17 005 6695 17 005 6695 17 005 Main Brg Dia Crankshaft Ball Bearing Magneto Side 9998 25 395 6691 16 995 6691 16 995 8745 22 212 8748 22 223 Main Brg Dia 1 0003 25 408 6695 17 005 6695 17 005 8750 22 225 8753 22 233 See Note A Crankshaft None None None None None None None None None End Play NOTE A Needle Bearing Se Does not apply to units with Solid State Ignition 56 TABLE OF SPECIFICATIONS Bee m es ler el Bore 2 093 53 162 2 093 53 162 2 093 53 162 2 093 53 162 2 093 53 162 2 094 53 188 2 094 53 188 2 094 53 188 2 094 53 188 2 094 53 188 Cu In Displacement in cc Spark Plug Gap Piston Ring 006
32. 152 007 178 007 178 006 152 006 152 End Gap 016 406 017 432 017 432 016 406 016 406 Piston 2 0870 53 01 2 0870 53 01 2 0870 53 01 2 0870 53 01 2 0875 53 01 Diameter 2 0880 53 035 2 0880 53 035 2 0880 53 035 2 0880 53 035 2 0885 53 035 Top 0655 1 664 0655 1 664 0655 1 664 0655 1 664 0655 1 664 Piston Ring 0665 1 689 0665 1 689 0665 1 689 0665 1 689 0665 1 689 Groove Width ES 1 ee E 1 Eg 0645 1 638 EJ 1 ES ES 1 EJ Bot ES 1 ee E 1 Eg 0655 1 664 EJ 1 ES ES 1 EJ Piston Ring 0615 1 562 0615 1 562 0615 1 562 0615 1 562 0615 1 562 Width 0625 1 587 0625 1 587 0625 1 587 0625 1 587 0625 1 587 Piston Pin 4997 12 692 4997 12 692 4997 12 692 4997 12 692 4997 12 692 Diameter 4999 12 697 4999 12 697 4999 12 697 4999 12 697 4999 12 697 Crank Pin Journal 6919 17 574 5614 14 26 5614 14 26 6919 17 574 6922 17 582 Diameter 6927 17 595 5621 14 277 5621 14 277 6927 17 595 6927 17 595 Crankshaft 6691 16 995 6691 16 995 6691 16 995 7498 19 045 6691 16 995 P T O Side 6695 17 005 6695 17 005 6695 17 005 7503 19 058 6695 17 005 Main Brg Dia Crankshaft 7498 19 045 6691 17 551 6691 17 551 6691 17 551 7498 19 045 Magneto Side 7503 19 058 6695 17 005 6695 17 005 6695 17 005 7503 19 058 Main Brg Dia Crankshaft None None None None None None None None End Play 57 TABLE OF SPECIFICATIONS za Ke ES Ed EMERGERE RIZ uns Bore 2 093 53 162
33. 18 Covers the diagnosis and repair of Peerless power train components 694782 Contains technical information for the repair of the TC series 2 cycle engines 694988 Contains diagnosis and technical information for the repair of TVS840 HSK HXL845 850 2 cycle engines 695244 A Covers the diagnosis and repair of the OVRM OVM OHH OHM OHV 4 cycle overhead valve engines 695578 Covers the diagnosis and repair of the Vector Series 4 cycle engines AVAILABLE FOREIGN TECHNICIAN S HANDBOOKS 694732 Spanish This manual covers the following models VH80 VH100 HH80 HH100 HH120 OH120 180 Model numbers are located on the engine shroud 695555 Spanish Covers the diagnosis and repair of the Tecumseh 4 cycle light medium frame engines 695657 German Covers the diagnosis and repair of the Tecumseh 4 cycle light medium frame engines 695562 French Covers the diagnosis and repair of the Tecumseh 4 cycle light medium frame engines VIDEO PROGRAMS 695015 Carburetor Troubleshooting Covers identification of carburetors used on Tecumseh engines and how to troubleshoot and repair them VHS only 695059 Understanding Tecumseh Ignition Systems A basic program designed to give the small engine technician first hand knowledge of Tecumseh ignition systems so the technician can understand the system and perform repairs to it VHS only 695148 Teardown and reassembly of the 900 series transaxles This video will show a complete
34. 2 093 53 162 2 093 53 162 2 093 53 162 2 093 53 162 2 my a 188 2 Be Eu 188 2 en pom 188 2 FER per 188 2 ES EE 188 Saige 1 rea 44 P ds a 44 n 1 em 1 Bo 44 m Cu In Displacement in cc Point Gap pm 1 321 2 235 T D C seg ES Steg Spark Plug Gap Piston Ring 152 d 152 152 152 End Gap SCH 152 Se CS 152 SCH 152 p 152 Piston 2 0875 53 023 2 0865 52 997 2 0875 53 023 2 0865 52 997 2 0865 52 997 Diameter 2 0885 53 048 2 0875 53 023 2 0885 53 048 2 0875 53 028 2 0875 53 023 Top 0655 1 664 0655 1 664 0655 1 664 0655 1 664 0655 1 664 Piston Ring 0665 1 689 0665 1 689 0665 1 689 0665 1 689 0665 1 689 Groove Width E 1 PS E 1 ee 0645 1 638 1 E E 1 Ed Bot E 1 PS E 1 ee 0655 1 664 1 E E 1 Ed Piston Ring 0615 1 652 0615 1 652 0615 1 652 0615 1 652 0615 1 652 Width 06251 587 0625 1 587 0625 1 587 0625 1 587 0625 1 587 Piston Pin 4997 12 692 4997 12 692 4997 12 692 4997 12 692 4997 12 692 Diameter 4999 12 697 4999 12 697 4999 12 697 4999 12 697 4999 12 697 Crank Pin Journal 6922 17 582 8113 20 607 8113 20 607 8113 20 607 8445 21 450 Diameter 6927 17 595 8118 20 620 8118 20 620 8118 20 620 8450 21 463 Crankshaft 7498 19 045 9998 25 395 7498 19 045 9998 25 395 9998 25 395 P T O Side 7503 19 058 1 0003 25 408 7503 19 058 1 0003 25 408 1 0003 25 408 Main Brg Dia Crankshaft 6695 17 005 6695 17 005 6695 17 005 7498 17 005 669
35. 26 Diameter 8450 21 463 6865 17 437 8450 21 463 6865 17 437 5621 14 277 Crankshaft 9998 25 395 8745 22 212 9998 25 395 8745 22 212 6691 16 995 P T O Side 1 0003 25 408 8750 22 225 1 0003 25 408 8750 22 225 6695 17 005 Main Brg Dia Crankshaft 6691 16 995 7495 19 037 7498 19 045 7495 10 037 6691 16 995 Magneto Side 6695 17 005 7500 19 05 7503 19 058 7500 19 05 6695 17 005 Main Brg Dia Crankshaft None None 003 076 d None None End Play 016 406 2 NOTE 2 642 24 26 29 B T D C 087 NOTE 3 643 13 B T D C 095 NOTE 4 643 93A 05A 13 14 020 54 TABLE OF SPECIFICATIONS Reference Column pee ce a ss Tu ros ra us p Vs qwe us wee Tus Dwee us s wee D us usu Bore 2 375 60 33 2 093 53 162 2 4375 61 913 2 093 53 162 2 093 53 162 2 ud new 35 2 F EN 188 2 E El 938 2 premi pati 188 2 pee 188 iux 1 meg 42 lod 1 m 1 end 44 ee 1 EN 1 Ese Cu In Displacement 122 9 133 9 in cc Point Gap Spark Plug Gap Piston Ring pu Es ps ps Ce End Gap ae ee ae Se SE Piston 2 3685 60 16 2 0870 53 01 2 4302 61 727 2 0875 53 023 2 0880 53 035 Diameter 2 3695 60 185 2 0880 53 035 2 4312 61 753 2 0885 53 048 2 0890 53 061 Top 0655 1 664 0975 1 664 0655 1 664 0645 1 638 0645 1 638 Piston Ring 0665 1 664 0985 1 689 0665 1 664 0655 1 664 0655 1 664 Groove Width 0645 1 638 0955 2 426 0645 1 638 0645 1 638 0645 1 638 Bot 0655 1 664
36. 32 53 01 53 035 1 664 1 689 1 638 1 664 1 562 1 587 12 692 12 697 14 260 14 277 16 995 17 005 16 995 17 005 None o o al U S Metric mm 2 093 2 094 53 162 53 188 1 410 35 814 78 7 o A c gt Ei E gt HB o e Ei 006 011 Em a 28 2 0875 2 0885 53 023 53 048 0655 0665 1 664 1 689 0645 0655 1 638 1 664 0615 0625 1 562 1 587 12 692 12 697 4997 4999 14 260 14 277 5614 5621 6691 6695 16 995 17 005 16 995 17 005 None None U S 2 093 2 094 53 162 53 188 1 410 35 814 4 80 N 030 a er al 006 014 2 0875 2 0885 53 023 53 048 0975 0985 1 664 1 689 0955 0965 1 638 1 664 0925 0935 2 35 2 375 3750 3751 9 525 9 528 6857 6865 17 417 17 437 6691 6695 16 995 17 005 6691 6695 16 995 17 005 None None Metric 53 162 53 188 2 093 2 094 1 410 stele 2 0875 2 0885 0655 0665 0645 0655 0615 0625 4997 4999 5611 5618 6691 6695 6691 6695 A 35 814 3 429 53 023 53 048 1 664 1 689 1 638 1 664 1 562 1 587 12 693 12 697 14 252 14 270 16 995 17 005 16 995 17 005 None TABLE OF SPECIFICATIONS Reference Column pec Ts v puse n cea pes Metric pee SS Metric EX Bea WR Edi EE Metric Bore 2 093 53 162 2 093 53 162 2 093 53 162 2 093
37. 5 17 005 Magneto Side 6699 17 015 6699 17 015 6699 17 015 7503 17 015 6699 17 015 Main Brg Dia Crankshaft None None None None None None None None 003 076 End Play 016 406 Does not apply to units with Solid State Ignition 58 TABLE OF SPECIFICATIONS Reference Column n A Fus use os as Fn Pe E Ma E id od Ko Bore 2 093 53 162 2 093 53 162 2 093 53 162 2 437 61 90 2 093 53 162 2 d Go 188 2 pui m 188 2 pm PA 188 2 p pem 925 2 en Pn 188 Bar 44 las 1 bessi 44 mm 1 m 1 RN 44 Pm 1 PA 44 Pw Cu In Displacement in cc Point Gap A a 1 854 1 854 2 845 2 235 T D C SE Spark Plug Gap Piston Ring Ss E Ge ne End Gap Ge Se Se Se P Piston 2 0865 52 997 2 0865 52 997 2 0882 53 04 2 4307 61 74 2 0880 53 035 Diameter 2 0875 53 023 2 0875 53 023 2 0887 53 05 2 4317 61 765 2 0885 53 049 Top 0655 1 664 0655 1 664 0655 1 664 0655 1 664 0655 1 664 Piston Ring 0665 1 689 0665 1 689 0665 1 689 0665 1 689 0665 1 689 Groove Width 0645 1 638 0645 1 638 0645 1 638 0645 1 638 0645 1 638 Bot 0655 1 664 0655 1 664 0655 1 664 0655 1 664 0655 1 664 Piston Ring 0615 1 562 0615 1 562 0615 1 562 0615 1 562 0615 1 562 Width 0625 1 587 0625 1 587 0625 1 587 0625 1 587 0625 1 587 Piston Pin 4997 12 692 4997 12 692 4997 12 692 4997 12 692 4997 12 692 Diameter 4999 12 698 4999 12 698 4999 12 698 4999 12 698 4999 12 698 Crank Pin Journal 8113 20 607 8445 21 45
38. 53 162 2 093 53 162 2 mm mu 188 2 EE b 188 2 Fe es 188 2 Ba Ech 188 2 pi pm 188 Ec 1 Be 1 WEEN 1 1 pay 1 ae Cu In Displacement in cc 4 699 1 778 100 2 159 1 D C Bar Note 1 Ze Note 2 Spark Plug Gap Piston Ring yn pos pus Ce End Gap py GC p pu p Piston 2 0870 53 01 2 0870 53 01 2 0870 53 01 2 0870 53 01 2 0870 53 01 Diameter 2 0880 53 035 2 0880 53 035 2 0880 53 035 2 0880 53 035 2 0880 53 035 Piston Ring Top 1 664 0655 1 664 0655 1 664 0655 1 664 0655 1 664 Groove Width 1 689 0665 1 689 0665 1 689 0665 1 689 0665 1 689 1 638 0645 1 638 0645 1 638 0645 1 638 0645 1 638 3 1 664 0655 1 664 0655 1 664 0655 1 664 0655 1 664 Piston Ring 0925 2 35 0615 1 562 0615 1 562 0615 1 562 0615 1 562 Width 0935 2 375 0625 1 587 0625 1 587 0625 1 587 0625 1 587 Piston Pin 3750 9 525 4997 12 692 4997 12 692 4997 12 692 4997 12 692 Diameter 3751 9 528 4999 12 697 4999 12 697 4999 12 697 4999 12 697 Crank Pin Journal 6857 17 417 5611 14 252 8442 21 443 6857 17 417 8442 21 443 Diameter 6865 17 437 5618 14 270 8450 21 463 6865 17 437 8450 21 463 Crankshaft 8745 22 212 6690 16 993 9998 25 349 8745 22 212 9998 25 349 P T O Side 8750 22 225 6694 17 003 1 0003 25 408 8750 22 225 1 0003 25 408 Main Brg Dia Crankshaft Ball Bearing Magneto Side 7495 19 037 6690 16 993 6691 16 995 7495 19 037 7498 19 045 Main Bro Dia 7500 19 05 6694 17 003 6695 17 005
39. 638 0645 1 638 0645 1 638 0645 1 638 Bot 0655 1 664 0655 1 664 0655 1 664 0655 1 664 0655 1 664 Piston Ring 0615 1 562 0615 1 562 0615 1 562 0615 1 562 0615 1 562 Width 0625 1 587 0625 1 587 0625 1 587 0625 1 587 0625 1 587 Piston Pin 4997 12 692 4997 12 692 4997 12 692 4997 12 692 4997 12 692 Diameter 4999 12 697 4999 12 697 4999 12 697 4999 12 697 4999 12 697 Crank Pin Journal 8113 20 607 8113 20 607 8445 21 450 8113 20 607 8113 20 607 Diameter 8118 20 620 8118 20 620 8450 21 463 8118 20 620 8118 20 620 Crankshaft 9998 25 395 9998 25 395 9998 25 395 9998 25 395 7498 19 045 P T O Side 1 0003 25 408 1 0003 25 408 1 0003 25 408 1 0003 25 408 7503 19 058 Main Brg Dia Crankshaft 7498 19 045 6695 17 005 6695 17 005 6695 17 005 6695 17 005 Magneto Side 7503 19 058 6699 17 015 6699 17 015 6699 17 015 6699 17 015 Main Brg Dia Crankshaft None None None None None None None None None None End Play Does not apply to units with Solid State Ignition 60 TABLE OF SPECIFICATIONS pete oe ps avezo aveo Ans aan SCH Bore 2 093 53 162 2 E Gi BER ha Cu In Displacement 85 cc 98 cc 98 cc 98 cc 98 cc in cc Ignition Module 0125 3175 0125 3175 0125 3175 0125 3175 0125 3175 Air Gap Spark Plug Gap Piston Ring Ps jas pun d pee po End Gap p p er p p jn Piston 2 0880 53 035 2 0877 53 03 2 0877 53 03 2 0877 53 03 2 0877 53 03 2 0877 53
40. BLY PROCEDURE 1 Pull out enough rope to lock the rope in the V of the bracket 2 Remove the handle if necessary by prying out the small staple in the handle with a screwdriver 3 Place the starter bracket on the top of a deep well socket that is large enough to receive the head of the center pin Use an arbor press to drive out the center pin 4 Rotate the spring capsule strut until it is aligned with the legs of the brake spring Insert a nail or pin no longer than 3 4 19 05 mm through the hole in the strut so it catches in the gear teeth This will keep the capsule in the wound position 5 Slip the sheave out of the bracket CAUTION DO NOT ATTEMPT TO REMOVE THE SPRING CAPSULE FROM THE SHEAVE ASSEMBLY UNLESS THE SPRING IS FULLY UNWOUND 6 Squeeze and hold tightly by hand the spring capsule at the outer edge against the gear sheave 7 Remove the retainer pin from the strut and slowly relieve the spring tension by allowing the spring capsule to rotate slowly under control until completely unwound The spring capsule can now be removed from the gear sheave 24 ROTATE Zem COUNTERCLOCKWISE E ASSEMBLY PROCEDURE 1 Feed the new rope through the hole and tie a left handed knot on the rope end Make sure the rope and knot do not protrude from the knot cavity and bind the pulley rotation ORIGINAL INSTALLATION WITH STAPLE INSTALL NEW ROPE BY TYING LEFT HAND KNOT PRY STAPLE REINSTALL TT LE
41. Check flywheel key and keyway replace parts if necessary Tighten flywheel nut to proper torque Replace cylinder Time magneto 2 CYCLE ENGINE TROUBLESHOOTING CHART Cont ENGINE MISSES UNDER LOAD Spark plug fouled Spark plug porcelain cracked Improper spark plug gap Pitted magneto breaker points Magneto breaker arm sluggish Faulty condenser Improper carburetor adjustment Reed fouled or sluggish Crankcase seal leak Clean and regap spark plug Replace spark plug Regap spark plug Clean and dress breaker points Replace badly pitted breaker points Clean and lubricate breaker point arm Check condenser on a tester replace if defective see test instrument instructions and specifications Adjust carburetor Clean or replace reed Replace worn crankcase seals ENGINE LACKS POWER Choke partially closed Blown head gasket Improper carburetor adjustment Improper or partially sheared flywheel key or adapter sleeve Magneto improperly timed Worn piston or rings Air cleaner clogged Reed fouled or sluggish Improper amount of oil in fuel mixture Carburetor improperly adjusted Crankcase seals leaking ENGINE OVERHEATS Engine improperly timed Improper or partially sheared flywheel key or adapter sleeve Air flow obstructed Cooling fins clogged Open choke Replace head gasket Adjust carburetor Replace with new correct key or sleeve Time magneto Replace piston or rings Cl
42. DENTIFICATION 6 FLOAT TYPE CARBURETORS 6 DIAPHRAGM PRESSURE DIFFERENTIAL CARBURETORS 5 1 a spe 6 OPERATION astra 7 CARBURETOR SERVICE sene 7 THROTTLE 2 2 so iris caida 7 CHONKE Ii ee aan 8 ADJUSTING SCREWS eese 8 FUEL BOWL RETAINING NUT 8 CARBURETOR VENTING esee 8 HIGH TILT FLOAT STYLE seen 8 FUEL BOWL 2 de re ka 8 FLOAT Zen E eres 8 INLET NEEDLE AND SEAT FLOAT CARBURETORS eee 9 NEEDLE AND SEAT OPO OFF TEST 9 FLOAT HEIGHT SETTINGS sense 9 PRIMER BULB 2 2 ee 10 CLEANING CARBURETOR BODY 10 DIAPHRAGMS 4 ae ia da 10 INLET NEEDLE AND SEAT nn 11 FUEL INLET EITTINOG nennen 11 Page PRIMER BULB DIAPHRAGM CARBURETOR Justo onerosa 11 CARBURETOR CHECK VALVE 11 CARBURETOR SERVICE PROCEDURE 12 EMISSIONIZED DIAPHRAGM CARBURETION 13 OUTBOARD CARBURETORS 13 OUTBOARD CONTROL PANEL 14 CARBURETOR ADJUSTMENTS 15 IDLE SPEED ADJUSTMENT ette 15 FLOAT TYPE FIXED MAIN IDLE ADJUST 15 DIAPHRAGM SINGLE AND DUAL ADJUSTMENT a2 ee 15 TROUBLESHOOTING CARBURETION 16 FLOAT CARBURETOR CHECKS 16 CHECKS FOR DIAPHRAGM ene 16 STANDARD SERVICE CARBURETORS
43. EVER UNTIL POINTS OPEN OUTBOARD TIMING SOLID STATE Follow these step by step procedures outlined for timing outboard engines with solid state magnetos FRICTION Using a dial indicator set the piston to the specified Before Top Dead Center BTDC dimension Install timing tool 670238A on the crankshaft be careful not to distort the keyway area Without disturbing the BTDC piston position move the control lever counterclockwise until the run trigger aligns with the timing tool 670238A notch marked 1 Hold this position NOTE Some models do not have the start trigger CONTROL POS 2 38A z THIS SIDE UP a RUN TRIGGER GROUND SCREW Adjust the stop bracket to prevent the control lever from moving any further counterclockwise Then tighten the stop bracket screw Loosen the actuating cam lock screw enough to allow adjustment of the cam Position the cam so that it opens the throttle completely making sure that the cam doesn t cause binding on the post When the correct position is attained tighten the lock screw on the high end to hold the cam in place THROTTLE ACTUATING LOCK SCREWS GREASE CAM SURFACE CONTROL LEVER Move the control lever to align the RUN trigger of the ignition unit with the number 2 position ofthe timing tool Hold this position TOOL 670238A THIS SIDE UP START TRIGGER RUN TRIGGER Adjust the actuating cam to touch the p
44. FT HANDED KNOT REMOVE OLD ROPE 2 Wind the rope on the sheave assembly clockwise viewing the gear from the gear side of the sheave 3 Reinstall the brake spring being careful not to spread the spring more than necessary 4 Install the spring capsule making sure the starter spring end hooks on the gear hub 5 Wind the spring four full turns and align the brake spring legs with the strut as shown Insert the pin in the strut GEAR HUB STARTER SPRING END SPRING HOOKED ON GEAR HUB ROTATE SPRING 4 FULL TURNS 6 Ifthe starter is equipped with a locking or delay pawl and spring make sure these are in place before HANDLE INSERT grasping the gear and spring capsule assembly f and sliding it into the bracket Make sure the legs of the brake spring are positioned in the slots of the bracket 7 Feedthe rope end under the rope guide and hook it into the V notch Remove the pin and the strut will rotate clockwise against the bracket 8 Insert the new center pin by pressing or driving the pin firmly in place Reinstall the starter assembly on the engine STARTER HANDLE ROPE BRAKE A p PULLEY HOUSING ASSY BRAKE SPRING TRUARC E CLIP SPRING A ASSY ASSEMBLY PROCEDURE 1 Hookloop of spring into housing and wind in housing in a counterclockwise direction The spring should have a light coating of grease on it 2 Place pulley into housing 3 Install dog spring and dog in starter pulley
45. H 1401J 1402 and 1402B 1425 1430A 1432 A 1440 A B C D 1442 A B 1444 A 1448 thru 1450 1450A A B C D E 1450F 1454 A 1459 1460 A B C D E F 1462 1464 A B 1465 1466 A 1471 A B 1472 A B C 1473 A B 1474 1475 thru 1476 1479 1482 A 1483 1484 A B C D 1485 1486 1488 A B C D 1489 thru 1490B 1491 1493 A 1494 and 1495A 1496 1497 1498 1499 1500 1501 A B C D E F G 1503 A B C D 1506 1506B 1507 1508 1509 1510 1511 1512 A 1513 1515 thru 1516C 1517 1518 MM a zl zl zl zl sl at O 1519 thru 1521 1522 1523 1524 1525A 1527 1528 A B 1529 A B 1530 A B 1531 1534A 1535B 1536 1537 1538 thru 1541A 1542 1543 thru 1546 1547 1549 1550A 1551 1552 1553 1554 A 1555 and 1556 1557 thru 1560 1561 1562 thru 1571 1572 1573 1574 thru 1577 1575 1578 1581 thru 1582A 1583 thru 1599A 1600 thru 1617 1618 thru 1619 1620 1622 thru 1623A 1624 thru 1642 AV 520 AV600 AH600 HSK600 TVS600 ON NONWH W WONHN SEARS CRAFTSMAN CROSS REFERENCE Craftsman Vertical Crankshaft Engines Craftsman No Column No 200 183112 200 183122 200 193132 200 193142 200 193152 200 193162 200 203112 200 203172 200 203182 200 203192 200 213112 200 213122 200 213132 200 223112 200 233112 200 243112 200 283012 200 2131128 200 2132228 Craftsman Horizontal
46. ING NUMBER When servicing carburetors you may use either the engine model specification number orthe manufacturing number on the carburetor to properly identify Information regarding replacement parts or kits are available in the master parts manual microfiche catalog or electronic parts look up systems Tecumseh uses two basic types of carburetors for their 2 cycle engines float type and diaphragm FLOAT TYPE CARBURETORS Float type carburetors use a hollow metal float to maintain the operating level of fuel in the carburetor As the fuel is used the fuel level in the carburetor bowl drops and the float moves downward This actuates the inlet needle valve to allow fuel to flow into the fuel bowl As the fuel level in the bowl again rises so will the float This float action adjusts the fuel flow and keeps the fuel at the proper mixture level Some carburetors are of the fixed main type On these models the main adjusting screw and nut are replaced by a fixed main jet bowl nut IDLE FUEL CHAMBER IDLE AIR BLEED CHOKE SHUTTER THROTTLE SHUTTER DISCHARGE PRIMARY IDLE DISCHARGE d d 2 1 T KoT A N ULM Me IDLE A T M ADJUSTMENT eycfs 22 Lakes IDLE FUEL TRANSFER PASSAGE IDLE FUEL TRANSFER PASSAGE MAIN ADJUST Both jets may be fixed non adjustable DIAPHRAGM CARBURETORS This type of carburetor uses a rubber like diaphragm which is exposed to intake manifold pressure on one side and to atmosph
47. REW 15 TROUBLESHOOTING CARBURETION POINTS TO CHECK FOR CARBURETOR MALFUNCTION TROUBLE CORRECTIONS Carburetor out of adjustment Engine will not start Engine will not accelerate Engine hunts at idle or high speed Engine will not idle Engine lacks power at high speed Carburetor floods Carburetor leaks Engine overspeeds Idle speed is excessive Choke does not open fully Engine starves for fuel at high speed leans out Carburetor runs rich with main adjustment needle shut off Performance unsatisfactory after being serviced1 1 Open fuel shut off valve at fuel tank Fill tank with fresh clean fuel 2 Check ignition spark plug and compression Clean air cleaner service as required 4 Dirt or restriction in fuel system clean tank and fuel strainers check for kinks or sharp bends 5 Check for stale fuel or water in fuel Fill with fresh fuel oil mixture of correct ratio Examine fuel line and pick up for sealing at fittings 7 Check and clean atmospheric vent holes 8 Examine throttle and choke shafts for binding or excessive play remove all dirt or paint replace shaft 9 Examine throttle and choke return springs for operation 10 Examine idle and main mixture adjustment screws and O rings for cracks or damage 11 Adjust main mixture adjustment screw Some models require finger tight adjustment Check to see that it is the correct screw 12 Adjust idle mixture adjustment screw Ch
48. RK OR PILOT LIGHT AS ON A FURNACE WATER HEATER CLOTHES DRYER ETC If engine is to be stored over 30 days prepare for storage as follows 1 Remove all gasoline from fuel tank to prevent gum deposits from forming in tank and other fuel system components causing possible malfunction of the engine DRAIN FUEL INTO APPROVED CONTAINER OUTDOORS AWAY FROM OPEN FLAMES Run engine until fuel tank is empty and engine stops due to lack of fuel Fuel stabilizer such as Tecumseh s Part No 730245 is an acceptable alternative in minimizing the formation of fuel gum deposits during storage Add stabilizer to fuel in fuel tank or storage container Always follow mix ratio found on stabilizer container Run engine at least 10 minutes after adding stabilizer to allow it to reach carburetor If gasohol has been used complete preceding instructions and then add a small amount one pint or less of unleaded regular automotive gasoline properly mixed with the specified lubricating oil and run the engine until the fuel tank is empty and the engine stops due to lack of fuel 2 Pull starter handle slowly until resistance is felt due to compression pressure then stop Release starter tension slowly to prevent engine from reversing due to compression pressure This position will close both the intake and exhaust ports to prevent corrosion of the piston and the cylinder bore 3 Clean unit by removing any dirt from exterior of the engine a
49. Rehook the link install the brake lever and pad assembly install the E clip rehook the short end of the spring and continue to reassemble the brake system in the reverse order of disassembly SHORT END OF SPRING ALIGN HOLES IGNITION GROUND OUT TERMINAL Inspect the ignition kill switch grounding clip for proper alignment and contact with the brake arm Insure that all electrical connections are clean and secure GROUNDING CLIP STARTER INTERLOCK SWITCH The engine blade control must close the interlock switch before the starter can be engaged To check the interlock switch use an ohmmeter or continuity light to perform a continuity check Continuity should exist between the two terminals when the interlock switch button is completely depressed No continuity should exist when the button is released Ifthe switch fails replace the switch To replace the interlock switch carefully grind the heads off ofthe rivets that fasten the interlock switch to the brake bracket Remove the rivets from the back side of brake bracket Use the self tapping screw supplied with the new switch to make threads in the bracket Install the interlock switch onto the brake bracket in the proper position and secure the switch to the brake bracket with the machine screws supplied Be careful not to overtighten the screws as switch breakage can occur SELF TAPPING SCREW MACHINE SCREWS CONTROL CABLE INSIDE EDGE If replacing the
50. TECUMSER TECHNICIAN S HANDBOOK This manual covers the following basic type or model numbers dependent on age of product AH520 AH600 AV520 AV600 HSK600 TVS600 This manual covered many engines under an Old form of Identification which will need to be reviewed as well TYPE SPECIFICATION NUMBER 638 670 1398 1642 and Craftsman 200 Series Models 2 CYCLE ENGINES TECUMSE WW Contents Page GENERAL INFORMATION 1 ENGINE IDENTIFICATION nenn 1 INTERPRETATION OF MODEL NUMBER 1 ENGINE CARE unusssssnannennnnnananannnnnnnnananannnnnnnnnnanann 2 SHORTBEOGKS EE 2 STORAGE Suar 2 TUNE UP PROCEDURE eene 3 EXHAUST PORT CLEANING sss 3 2 CYCLE THEORY OF OPERATION 4 OPERATION OF PISTON PORT STYLE 4 OPERATION OF REED PORTED STYLE WITH LOOP SCAVENGING 4 TERMS 1425 5 22 22 4 EXHAUST OR SCAVENGE PHASE oaaae 4 PORTS 2222 28 Aut beter ise ee IS 4 EXHAUST PORTS terti eat 4 THIRD PORT 2 REPERI 4 REED WAIVE i ae oes 4 LUBRICATION Ane appia aeta anaana aeaiiai 4 AIR CLEANERS CARBURETORS GOVERNORS AND LINKAGE ccnoonoccococccnnnnnnnncnnencnnnnnnannnnnnnnnnnanncnnn 5 AIR CLEANERS AAA 5 POLYURETHANE TYPE AIR CLEANER 5 KLEEN AIRE SYSTEM e 5 PAPER TYPE AIR CLEANER SERVICE 5 GENERAL CARBURETOR INFORMATION 6 CARBURETOR I
51. VARIABLE SPEED MANUAL CONTROL SPRING HIGH SPEED RPM IDEE REM ADJUSTMENT ADJUSTMENT IDLE MATURE THIS HOLE NOT PRESENT ON ALL MODELS SPRING VERTICAL ENGINE VARIABLE SPEED REMOTE CONTROL IDLE RPM ADJUSTMENT MIXTURE THIS HOLE NOT PRESENT ON ALL MODELS VERTICAL ENGINE FIXED SPEED REMOTE CONTROL THIS HOLE NOT PRESENT ON ALL MODELS SPRING VERTICAL ENGINE FIXED SPEED 19 REWIND STARTERS ELECTRIC STARTERS AND ALTERNATORS REWIND STARTERS GENERAL INFORMATION Rewind starters used on vertical shaft Tecumseh engines are top mount horizontal pull style or side mount vertical pull style Horizontal shaft engines use side mounted starters which can be mounted to pull either vertically or horizontally All rewind starters except the vertical pull style turn the engine over by engaging a dog s into the starter cup attached to the engine flywheel The vertical pull starter engages the starter gear into the ring gear of the flywheel to turn the engine over All starters are spring loaded to retract the dog s or starter gear when the engine speed exceeds the turning speed of the starter OPERATION As the starter rope is pulled the starter pulley rotates on the center pin The starter dog s is pinned or pocketed in the pulley hub and extends outward when the pulley s rotation forces the starter dog s to contact the ears on the retainer The retainer ears act as a ramp to fully extend the starter do
52. al calibration of these engines All speed adjustments must remain within the limits that are specified for each engine and are not to exceed the maximum Any deviation must be specifically approved by Tecumseh Products Company GENERAL INFORMATION ENGINE IDENTIFICATION Tecumseh has used two different methods of identifying 2 cycle engines The first method was used until the mid 1980 s using the base model number with atype number The type number was used to identify variations for the OEM s specific needs Fig 1 FRONT SIDE O TECUMSEH 6874603 SERIAL NUMBER 1975 YEAR 80th DAY 5th MONTH MAY REVERSE SIDE BUILD DATE 670 100 TYPE O TECUMSEH 6219 SERIAL 62290322 NUMBER Ur T _ YEAR 229th DAY fee ee 1976 or Aug 17th 1401J TYPE Q TECUMSEH SERIAL NUMBER The second method was put in place to standardize 2 cycle and 4 cycle engine identification The type number has now become the specification number which is preceded by the engine model as illustrated in Figure 2 and 3 TVS600 661030M 7352 INTERPRETATION OF MODEL NUMBER The letter designations in a model number indicates the basic type of engine AH Aluminum Horizontal AM Aluminum Vertical BV Outboard Vertical HSK Horizontal Snow King TVS Tecumseh Vertical Styling The numbers that follow the letter designations indicate the horsepower or cubic inch displacement Following the en
53. and bind the pulley rotation RETAINER REPLACEMENT 1 Remove the starter handle if the retainer is a complete circle design Remove the staple and old retainer 2 Slide the rope retainer into the proper position and insert the staple using a pliers 3 Install the starter handle and tie a left hand knot to secure the handle r Er ONE PIECE ROPE RETAINER Disassembly Procedure 1 After removing the rewind assembly from the engine blower housing release the tension on the rewind spring This can be done by removing the starter handle and carefully allowing the rope to unwind in the starter housing assembly 2 Place a 1 25 mm deep well socket under the retainer Set the rewind on a bench supported on the socket 3 Use a 5 16 7 938 mm or 1 4 6 35 mm for stamped steel roll pin punch to drive out the center pin The stamped steel center pin is driven out from the top inside the center hole Move the punch around while driving the pin to help keep the pin straight CAUTION THIS REWIND SPRING IS NOT SECURED IN A CANISTER PULLEY BOSSES HOLD THE REWIND SPRING AND COVER AND CAN BE EASILY DISLODGED DURING HANDLING 4 Remove the brake spring spring retainer washers and pulley assembly diag 7 8 9 4 10 NOTE The starter dogs face out on the stamped steel starter and the dogs face in on the stylized rewind starter 5 All components in need of service should be replaced HANDLE PULLEY
54. des consumer safety by shutting down the engine and lawnmower blade within seconds afterthe operator releases the Engine Blade control at the handle of the lawnmower INSIDE EDGE SYSTEM In the stop position the brake pad is applied to the inside edge of the flywheel at the same time the ignition system is grounded In order to restart the engine the brake control must be applied This action pulls the brake pad away from the inside edge of the flywheel and opens the ignition kill switch On electric start systems the starter is energized by an ignition switch or a two motion control On non electric start systems the recoil starter rope must be pulled to start engine IGNITION OPEN BRAKE RELEASED COMPONENTS The Inside Edge system uses the following components The brake lever and pad assembly consists of a steel lever with a brake pad bonded to the lever The ignition kill switch is a plastic block with a wire extending out of it The wire is attached to a terminal which is connected to the ignition kill wire The brake lever contacts and grounds the wire of the switch when the engine blade control is released and the ignition module is grounded This in turn kills the ignition The interlock switch is a push button switch that is activated by the brake lever when the engine blade control is actuated If there is a starter switch used to start the engine the interlock switch acts as a safety switch and will not allow
55. e fresh gasoline only Gasoline standing for long periods of time develop a gum that will result in fouled spark plugs clogged fuel lines carburetors and fuel screens 2 Using fuel that is not fresh will cause engines to be hard starting especially in cold temperatures Clean gas cap tank and fuel container spout when filling fuel tank to assure that dirt will not get into fuel system If gasohol is used special care is required when the engine is to be stored for extended periods ENGINE OIL Use Clean high quality 2 CYCLE OIL NMMA TC WII or TC W3 FUEL OIL MIX Follow fuel and engine oil requirements listed in the Owner s Manual Disregard conflicting instructions found on oil containers NOTE Sears Craftsman models use a 40 1 mix which is acceptable NOTE ALWAYS DOUBLE THE AMOUNT OF OIL FOR THE FIRST GALLON OF MIX FOR ENGINE BREAK IN To assure thorough mixing of oil and gasoline fill container with gasoline to one quarter full add oil as recommended shake container vigorously and then add remainder of gasoline Do not mix directly in engine or equipment fuel tank TWO CYCLE FUEL OIL MIX RATIOS 24 1 AV520 All Basic Specifications 670 amp 653 AV600 All Basic Specifications 600 10 amp Up 32 1 TVS600 All Specifications AH600 50 1 HSK600 STORAGE NEVER STORE ENGINE WITH FUEL IN TANK INDOORS OR IN ENCLOSED POORLY VENTILATED ENCLOSURES WHERE FUEL FUMES MAY REACH AN OPEN FLAME SPA
56. ean air cleaner Clean or replace reed Drain tank fill with correct mixture See engine decal Adjust carburetor Replace worn crankcase seals Time engine Replace with new correct key or sleeve Remove any obstructions from air passages in shrouds Clean cooling fins 2 CYCLE ENGINE TROUBLESHOOTING CHART Cont ENGINE OVERHEATS continued Excessive load on engine Check operation of associated equipment Reduce excessive load Carbon in combustion chamber Remove cylinder head or cylinder and clean carbon from head and piston Improper amount of oil in fuel mixture Drain tank fill with correct mixture ENGINE SURGES OR RUNS UNEVENLY Fuel tank cap vent hole clogged Open vent hole Crankcase air leak Inspect and replace gasket or seal Governor parts sticking or binding Clean and if necessary repair governor parts Carburetor throttle linkage or throttle shaft and or Clean lubricate or adjust linkage and deburr throttle butterfly binding or sticking shaft or butterfly ENGINE VIBRATES EXCESSIVELY Engine not securely mounted Tighten loose mounting bolts See equipment instructions Bent crankshaft Replace crankshaft Driven equipment out of balance Recheck driven equipment Piston installed incorrectly Engines with wrist Install piston correctly pin offset SPECIFICATIONS ENGINE TYPE NUMBER AND LETTER REFERENCE Tecumseh has used two different methods of identifying 2 cycle engines The fi
57. eck to see that it is the correct screw 13 Adjust idle speed screw 14 Check position of choke and throttle plates 15 Adjust control cable or linkage to assure full choke and carburetor control 16 3 4 11 12 13 15 20 1 2 3 4 5 6 8 9 10 11 12 14 15 16 17 19 21 24 25 2 3 4 5 11 12 19 24 3 4 8 9 10 11 12 14 20 21 24 26 27 3 4 8 9 10 11 12 13 14 18 20 21 22 24 25 26 27 2 3 4 6 8 10 11 12 15 18 19 20 21 24 25 26 4 7 17 21 22 25 26 4 6 7 10 17 18 23 24 25 8 9 11 14 15 18 20 8 9 13 14 15 18 20 25 26 27 8 9 14 15 1 3 4 5 6 10 11 15 16 17 18 19 21 25 26 7 8 9 11 14 17 18 19 21 25 26 D 3 4 5 6 7 8 9 10 11 12 14 15 16 17 18 19 20 21 24 25 26 16 Clean carburetor after removing all non metallic parts that are serviceable Trace all passages 17 Check inlet needle and seat for condition and proper installation 18 Check sealing of welch plugs cups plugs and gaskets 19 Check fuel pump operation pump element inner and outer one way valves 20 Adjust governor linkage FLOAT CARBURETOR CHECKS 21 Adjust float setting 22 Check float shaft for wear and float for leaks or dents 23 Check seal for fuel drain or bowl gasket 24 Is carburetor operating at excessive angle CHECKS FOR DIAPHRAGM 25 Check diaphragm for cracks or distortion and check nylon check ball for function 26 Check sequence of gasket and diaphragm forthe particular carburetor being repaired 27 Check spring tension on idle gove
58. el pump consisting of a fuel pump element which inflates and deflates with crankcase pulses which opens and closes two flap valves in the fuel pump thereby pumping fuel from a remote tank to the carburetor float bowl When replacing the fuel pump element install with the slot opening at a 45 angle as illustrated FUEL PUMP ELEMENT 13 Asthe engine s piston moves upward a partial vacuum is created in the crankcase which collapses the fuel pump element in the carburetor On the outside ofthe element suction opens the inlet flap drawing a supply of fuel from the tank and lines into the cavity created by the deflating pump element Suction pulls the outlet flap closed sealing the outlet port so that fuel isn t pulled from the area of the inlet needle and seat FUEL PUMP ELEMENT DEFLATED 4 INLET FLAP VALVE enlarges the pump element forcing fuel out of its cavity This pressurized fuel acts against the outlet flap valve opening it allowing a head of pressurized fuel to be transmitted to the inlet needle and seat port The inlet valve is pressed against the inlet port sealing it so that pressurized fuel does not escape back into the fuel tank and lines The flap valves are located between the cover and FUEL PUMP ELEMENT INFLATED INLET FLAP S gasket Make sure the flaps are in good condition and the strainer is not clogged or damaged Replace as necessary Make sure the cover is not warped check by
59. emedy and Reference ENGINE FAILS TO START OR STARTS WITH DIFFICULTY No fuel in tank Fuel shut off valve closed Obstructed fuel line Tank cap vent obstructed Water in fuel Engine overchoked Improper carburetor adjustment Loose or defective magneto wiring Sheared or incorrect flywheel key or adapter sleeve Faulty Magneto Spark plug fouled Crankcase seals and or gaskets leaking Spark plug porcelain cracked Poor Compression Exhaust ports plugged ENGINE KNOCKS Carbon in combustion chamber Loose or worn connecting rod Loose flywheel Worn cylinder Improper magneto timing Filltank with clean fresh fuel with correct oil ratio Open valve Clean fuel screen and line If necessary remove and clean carburetor Open vent in fuel tank cap or replace cap Drain tank Clean carburetor and fuel lines Dry spark plug points Fill tank with clean fresh fuel Close fuel shut off and pull starter until engine starts Reopen fuel shutoff for normal fuel flow immediately after engine starts Adjust carburetor Check magneto wiring for shorts or grounds repair if necessary Replace with correct key or adapter sleeve Check timing point gap and if necessary overhaul magneto Clean and regap spark plug Replace seals and or gaskets Replace spark plug Overhaul engine Clean exhaust ports Remove cylinder head or cylinder and clean carbon from head and piston Replace connecting rod
60. en them and sliding it back and forth Then open points and remove paper and any paper fiber remaining between the point set Any oil fingerprints or contamination will cause the points to burn prematurely CONDENSER CHECK Check condenser on a good quality tester following the test equipment manufacturer s instructions to check capacity and resistance Replace condenser if condition is questionable IGNITION COIL Inspect the coil for cracks in insulation or other damage Make sure electrical leads are intact especially where they enter the coil Check operation of the coil using an approved tester following the instructions furnished with the test unit If laminations are distorted or damaged replace Some coils are permanently attached to the laminations and must be serviced as an assembly IGNITION TIMING Begin procedure by setting the point gap This is done by rotating the crankshaft until the point arm is resting on the high side of the ignition cam Set the point gap by loosening the screw on the movable point and insert a feeler gauge per specification Tighten the screw then recheck the gap AR POINTS Install dial indicator Part No 670241 equipped with the correct tip on the extender leg Use the small tip for engines with timing dimensions of between Top Dead Center and 050 1 27 mm BTDC Use the large tip for engines with timing dimensions of between 051 1 29 mm BTDC to 150 3 81 mm BTDC Loosen
61. eric pressure on the other Tecumseh diaphragm carburetors use the diaphragm as a metering device As the intake manifold pressure decreases due to downward piston travel the atmospheric pressure on the vented side of the diaphragm moves the diaphragm against the inlet needle The diaphragm movement overcomes the spring tension on the inlet needle and moves the inlet needle off the seat This permits the fuel to flow through the inlet valve to maintain the correct fuel volume in the fuel chamber The inlet needle return spring closes the inlet valve when the pressure on the diaphragm equalizes or a pressure higher than atmospheric exists on the intake side upward piston travel The diaphragm meters a correct fuel volume in the fuel chamber to be delivered to the mixing passages and discharge ports PRESSURE DIFFERENTIAL A main or idle adjustment needle may be replaced by an internally fixed jet on some models The main nozzle contains a ball check valve The main purpose of this ball check is to eliminate air being drawn down the main nozzle during idle speeds and leaning the idle mixture An advantage of the diaphragm carburetor over the float system is that the diaphragm carburetor increases the angle that the engine may be operated at AIR BLEED IDLE AND INTERMEDIATE f7 PORTS THROTTLE SHUTTER DIAPHRAGM OPERATION In the CHOKE or START position the choke shutter is closed and the only air entering the engi
62. g between contacts Using a dial indicator set the piston to the proper Before Top Dead Center BTDC to the specified dimension Remove leads from point terminal then reinstall and tighten the nut and washer Attach a continuity device to the point terminal post and to a good ground on the engine as shown LEADS REMOVED TERMINAL POST NUT AND WASHER Move the stator counterclockwise advancing the timing until the continuity reading breaks and reads zero Tighten the stop bracket to secure the stator Loosen the actuating cam locking screws just enough to allow adjustment of the cam Move the actuating cam to open the throttle completely WITHOUT causing any binding with the throttle post LOCKING SCREWS GREASE CAM SURFACE STOP BRACKET THROTTLE ACTUATING THROTTLE POST To coordinate the carburetor idle with ignition timing rotate the crankshaft clockwise to 003 After Top Dead Center ATDC Rotate the control lever toward the idle position until continuity is obtained Move the throttle actuating cam until it just touches the throttle post without moving it Tighten the screw slightly then check the run position and idle position alternately to make sure the actuating cam is adjusted for both positions Now tighten the screws KEEP CONTINUITY LEADS ON TERMINAL POST AND GROUND THROTTLE ACTUATING CAM SET CAM SO THAT IT JUST TOUCHES THE THROTTLE LEVER POST MOVE CONTROL L
63. g below the top surface of the carburetor After installing the welch plug seal the outer diameter with finger nail polish Do not use clear polish FLAT END PUNCH SAME OR LARGER DIAMETER OF PLUG E m ER THROTTLE Examine the throttle lever and plate prior to disassembly Replace any worn and or damaged parts NEW WELCH PLUG When reassembling it is important that the lines on the throttle plate are facing out when in the closed position Position throttle plates with the two lines at 12 and 3 o clock If throttle plate has only one line the line should be positioned in the 12 o clock position If binding occurs correct by loosening the screws and repositioning the throttle plate THROTTLE LEVER N CHOKE Examine the choke lever and shaft at the bearing points and holes into which the linkage is fastened and replace if worn or damaged The choke plate is inserted into the air horn of the carburetor in such a position that the flat side of the choke is down Before disassembly note the direction of choke plate movement Choke plates will operate in either direction Make sure it is assembled properly for your engine CHOKE PLATE DOWN TOWARD FUEL BOWL ADJUSTING SCREWS Remove the adjusting screws from the carburetor body and examine the point replace the screws if damaged Tension is maintained on the screw with a coil spring Examine and replace the O ring seal s if damaged NOTE If screws are made
64. g s The fully extended starter dog s locks in contact with notches in the starter cup When the engine fires and the rotational speed of the starter cup exceeds the starter pulley the starter dog s disengages from the starter cup The starter dog spring s returns the starter dog s to the disengaged position The recoil spring turns the starter pulley in the opposite direction retracting the starter rope until the handle contacts the stop COMPONENTS HANDLE SE 7 ROPE STARTER HOUSING PULLEY AND REWIND SPRING ASSY STARTER DOG 4 icu Aa HER CS RETAINER BRAKE SPRING amp WASHER SPRING PIN 20 SERVICE Starter related problems will require the starter to be removed from the engine to diagnose the cause Visually inspect the starter dog s starter cup retainer springs rope washers and the starter pulley for wear or breakage Use one of the following procedures that applies to your application to disassemble repair and assemble the starter Always consult the Tecumseh Master Parts Manual for the correct replacement parts ROPE SERVICE Rope replacement should be done using the correct part number replacement rope or braided rope of the correct diameter and length Consult the Tecumseh Master Parts Manual to obtain the correct part number length and size required Use the following rope chart to convert a numbered rope to a fractional diameter for bulk rope use 4 1 2 rope
65. gine size are the engine specification numbers which are used for identification when ordering parts The final set of numbers are the date of manufacture D O M Example HSK600 1688S HSK Horizontal Snow King 600 6 Cubic Inch displacement 16888 Specification number 8023B Serial number D O M date of manufacturing previously serial number 8 First digit is the year of manufacturing 1998 023 Indicates the calendar day of the year 23th day or Jan 23 1998 B Represents the line and shift on which the engine was built at the factory IMPORTANT ENGINE INFORMATION TECUMSEH PRODUCTS CO FUEL REGULAR UNLEADED FUEL OIL MIX 32 1 HSK600 1688S 8023B D O M SER CAUTION FOR PERSONAL PROTECTION REFER TO A OWNER S MANUAL FOR IMPORTANT SAFETY AND MAINTENANCE INFORMATION ENGINE MODEL ENGINE FAMILY DISPLACEMENT Tecumseh engine model specification and D O M number are now located on a decal adhered to the blower housing IMPORTANT ENGINE INFORMATION TECUMSEH PRODUCTS CO FUEL REGULAR UNLEADED FUEL OIL MIX 32 1 e HSK600 1688S va 8023B e AU HIN ENGINE CARE SHORT BLOCK IDENTIFICATION TAG SBV OR SBH IDENTIFICATION NUMBER SBV 2316 SER 4291 SERIAL NUMBER SHORT BLOCKS New short blocks are identified by a tag marked S B H Short Block Horizontal or S B V Short Block Vertical Original model identification numbers of an engine sho
66. he brass type check valve drill a 9 64 3 57 mm hole through the center of the check valve making sure drill does not travel more than 1 8 3 17 mm into the body and damage the carburetor Turn a nut on to a 8 32 tap and slide a washer on after it Turn the tap with nut and washer into the valve until the tap begins to protrude through the valve when viewed through the inlet needle and seat opening Turn the nut clockwise to pull the valve out from the carburetor body 8 32 TAP WASHER The teflon disc type can be cleaned by using low air pressure forced into the inlet fitting If service is required pull out inlet fuel fitting and replace the teflon disc Put a drop of oil on the disc and position in the cavity of the carburetor Replace fuel inlet fitting as outlined in Fuel Inlet Fitting instructions TEFLON 11 CARBURETOR SERVICE PROCEDURE THROTTLE SHAFT AND LEVER IDLE SPEED ADJUSTMENT SCREW Dosen ant it just Sea Check shaft for looseness or binding uote ever then turn screw in Shutter must be positioned with THROTTLE SHUTTER a u Do not attempt to remove Blow air parallel with shaft DETENT MAIN NOZZLE y REFERENCE MARK through passage CHOKE SHAFT AND LEVER Check shaft for binding CHOKE PLATE Check spring for return action THROTTLE SHAFT and binding RETURN SPRING MAIN NOZZLE Blow air through passage Do not re AIR BLEED move restrictor if prese
67. ing when it strikes the cylinder head thus forcing all spent gases out through the open exhaust ports TERMIS Listed are common terms often referred to on 2 cycle engines EXHAUST or SCAVENGE PHASE The burned gases must be cleared out of the combustion chamber and replaced by a fresh charge of fuel air mixture through the intake ports The exhaust passes out through the exhaust ports into the outside air PORTS Openings in the cylinder allow gases to pass into and out of the combustion chamber The ports are opened or closed by the upward and downward movement of the piston EXHAUST PORTS Allow the burned gases to pass out of the combustion chamber THIRD PORT Sometimes called piston port A third port is for entry of the fuel air and oil mixture to the crankcase From the crankcase the fuel air mixture enters the combustion chamber through the intake ports The third port is controlled by the piston skirt REED VALVE Areed valve is activated by crankcase pressure or vacuum A decrease in crankcase pressure opens the reed allowing the fuel air and oil mixture to enter the crankcase Increased crankcase pressure closes the valve preventing escape of the fuel air and oil mixture back through the carburetor LUBRICATION Tecumseh 2 cycle engines are lubricated by a gas oil mix The correct mix ratio of oil and gas combines with air in the venturi and enters the crankcase During engine operation the oil clings to all the inte
68. is booklet is designed to be used as a work bench quick reference guide when servicing Tecumseh engines and motion drive systems TESTER BOOKLETS 694529 Test procedures for Tecumseh electrical components using Graham Lee Tester 31 SM or 31 SMX H 694530 Test procedures for Tecumseh electrical components using Merco O Tronic Tester 9800 Tests are similar for 98 98A and 79 63 TOOL KIT 6 70195D A Ww 670294 670305 STRAP WRENCH 670306 FLYWHEEL PULLER 670299 FLYWHEEL PULLER VALVE SPRING COMPRESSOR FOR OH120 180 670315A J VALVE SPRING COMPRESSOR FOR OVM OVXL120 125 OHV 11 17 A ey 670297 670321 AIR GAP GAUGE AIR GAP GAUGE 0125 030 670237A 670324 670323 670334 670333 670320 670319 64 OIL SEAL DRIVER PROTECTOR DIAL INDICATOR Extra Tips Large Head No 670250 Thin Head No 670249 Leg and Screw No 670296 No 670241 Dial Indicator No 670286 Used on P T O end of single cylinder outboards with one piece oil seals Includes tool No 670285 and center screw No 670291 Used on magneto end of all two cycle engines with one piece oil seals and P T O end of 1600 series Includes tool No 670280 and center screw No 670257 Used on 2 cycle connecting rod screws No 670307 Used on 590556 electric starter mounting screws TORX E 6 SOCKET eE No 670257 TORX E 8 SOCKET No 670307 BALL BEARING DRIVER No 670258 PISTON RING
69. is voltage is transferred by means of the high tension lead to the spark plug where it arcs across the electrode of the spark plug and ignites the fuel air mixture TO HUT OFF SWITCH ELECTRONIC SCR E PULSE TRANSFORMER 2 amp TRIGGER SPARK PLUG 32 IGNITION SERVICE SPARK PLUG SERVICE Spark plugs should be cleaned and adjusted periodically Check point gap with wire feeler gauge 030 762 mm and adjust gap Replace if points are pitted and burned orthe porcelain is cracked Referto Master Parts Manual or Micro Fiche for correct replacement number If spark plug fouls frequently check for the following conditions Carburetor set too rich Choke not opening fully Poor grade gasoline Clogged exhaust system Incorrect spark plug Improper oil fuel ratio Inconsistent spark NOTE Ensure cleaned spark plugs are free of all foreign material before installation NDS NT FLYWHEEL REMOVAL AND SERVICE To remove flywheel use a strap wrench Part No 670305 to hold the flywheel and remove the nut by turning it in the direction opposite of crankshaft rotation STRAP WRENCH NOTE Do not attempt to remove flywheel using a jaw type pullers on the outer diameter of the flywheel or flywheel breakage will occur On engines with cored holes not tapped use flywheel puller part No 670306 FLYWHEEL PULLER 670306 NOTE A KNOCK OFF TOOL IS NOT RECOMMENDED FOR ENGINES WITH A BALL BEARING ON THE
70. ity force The air vane pivots on the engine flange 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 LINKAGE INSTALLATION The best method is to record the linkage attachment points prior to disassembly and reinstall the same way Illustrations showing most governor and linkage hookups are pictured in this section Select the diagram that resembles the engine you are servicing R P M settings may be found in microfiche catalog card number 30 AIR VANE antl Sara SEE OQ LZ ee IS Rotate sleeve clockwise to increase R P M counterclockwise to decrease R P M NOTE The sleeve is serrated to rotate in a clockwise direction and must be raised using the sleeve tabs before it can be rotated counterclockwise To disassemble remove choke shutter with needle nose pliers the vane assembly may then be removed from the carburetor 18 AIR VANE ASSEMBLY BEND TAB TO ADJUST RPM HORIZONTAL FIXED SPEED PLASTIC AIR VANE GOVERNOR ADJUST RPM BY LOOSENING SCREW AND SLIDING BRACKET R HORIZONTAL FIXED SPEED ALUMINUM AIR VANE GOVERNOR ADJUST RPM BY LOOSENING SCREW AND SLIDING BRACKET LINK NE lt d 7 GOVERNOR HIGH SPEED RPM ADJUSTMENT THIS HOLE NOT PRESENT ON ALL MODELS VERTICAL ENGINE
71. lized Use the ohm readings in the chart below for the type that you are servicing Readings should be as follows Type A Type B Type C 100 to 200 Over 50 000 100 to 200 Ohms Ohms Ohms 28 MOUNTED ON BLOWER HOUSING OR COVER PLATE VIEW FROM BOTTOM OHM METER FLYWHEEL INSIDE EDGE BRAKE SYSTEM Tecumseh s brake systems provide two methods of meeting compliance standards which has become a Federal law as of June 30 1982 There are two additional methods used by equipment manufacturers that also meet compliance standards they are 1 Use of the blade brake clutch in conjunction with either atop or side mounted recoil starter The blade stops within three seconds after the operator lets go of the blade control bail at the operator position and the engine continues to run Starter rope handle is on the engine 2 Use of a recoil starter top or side mounted with the rope handle on the engine as opposed to within 24 inches from the operator position This method is acceptable if the mower deck passes the 360 degree foot probe test A specified foot probe must not contactthe blade when applied completely around the entire blade housing This alternative can be used with engine mounted brake systems and typical bail controls The blade stops within three seconds after the operator lets go of the blade control bail atthe operator position and the engine is stopped Tecumseh s Flywheel Inside Edge Brake System provi
72. lling the piston into the bore put oil on the rings and piston and stagger the ring end gaps STAGGER RING END GAPS Most models have offset pistons The pistons on these models have a V or S stamped on the piston head When installing piston this V mark must be in a 3 o clock position when viewing the engine with the exhaust ports down S OR V MARK AT THE 3 O CLOCK POSITION AND THE EXHAUST PORTS DOWN 41 CONNECTING ROD SERVICE Two cycle engines may be equipped with steel or aluminum connecting rods Aluminum connecting rods use steel liners when needle bearings are utilized The connecting rod bolts used are Torx size E6 If torx sockets are not locally available they can be purchased through your Tecumseh parts supplier under part number 670257 The connecting rod bolts should be tightened alternately and torqued to proper specification All connecting rods have match marks on the connecting rod and cap Make certain these match marks are aligned when assembling MATCH MARKS MATCH MARKS NEEDLE BEARINGS Needle bearings may be single or split row Split needles are to be installed with the blunt ends together and tapered ends outward SINGLE NEEDLE g SPLIT NEEDLE Service needles are supplied with a coating to hold the needles together and make installation easier Remove the paper backing on the bearings and wrap uniformly around the crankshaft journal Pull the co
73. m the carburetor body This will also lift the inlet needle out of the seat Examine the float for damage Check the float hinge bearing surfaces for wear as well as the tab that contacts the inlet needle Replace any damaged or worn parts EXAMINE FLOAT HINGE FOR WEAR AT BEARING SURFACES INLET NEEDLE REMOVE FLOAT TO MAKE ADJUSTMENTS BEND THIS TAB TO ADJUST Float sticking can occur due to fuel deposits gum or vamish This can be corrected by loosening the carburetor bowl nut one full turn and rotating the bowl 1 4 turn in either direction Return the bowl to it s original position and retighten the bowl nut INLET NEEDLE AND SEAT FLOAT CARBURETORS Tecumseh carburetors are built with removable seats made out of a material called VITON These seats are easily removed by bending the end of a paper clip or wire with a 3 32 hook or use a 4 crochet hook Push the hook through the hole in the center ofthe seat and remove it Never reuse the old seat always replace it with a new seat To install a new seat make sure the seat cavity is clean then moisten the seat with a drop of oil to help it slide into place Position the seat with the grooved side of the seal down and carefully push the seat into its cavity with a 5 32 flat punch until it bottoms out NEEDLE AND SEAT POP OFF TEST To test the pop off pressure remove the carburetor from the engine Be sure to drain any fuel into an approved container Invertthe carburet
74. n nozzle opening Fuel is forced out the main nozzle opening due the difference in the atmospheric air pressure on the fuel in the carburetor bowl and the reduced air pressure at the main nozzle opening CARBURETOR SERVICE Carefully disassemble carburetor removing all non metallic parts i e gaskets viton seats and needles O rings fuel pump valves etc Nylon check balls used in some diaphragm carburetors are not serviceable Nylon can be damaged if subjected to harsh cleaners for prolonged periods Remove the primer bulb if equipped by grasping with a pliers and pulling and twisting out of the body Remove the retainer by prying and lifting out with a screwdriver Do not re use old bulb or retainer Remove all welch plugs if cleaning the carburetor Secure the carburetor in a vise equipped with protective jaws Use a small chisel sharpened to a 1 8 wide wedge point Drive the chisel into the plug to pierce the metal and push down on the chisel to pry the plug out of the hole Clean all metallic parts with solvent SMALL CHISEL PIERCE PLUG WITH TIP PRY OUT PLUG WELCH PLUG TO BE REMOVED DO NOT ALLOW a oe POINT TO STRIKE CARBURETOR BODY OR CHANNEL REDUCER o 1 8 WIDE SMALL CHISEL SCH To install anew welch plug after cleaning place welch plug into receptacle with raised portion up With a punch equal to the size of the plug merely flatten the plug Do not dent or drive the center plu
75. nals or cutting the connections and then resoldering Ifthe brush card is warped from overheating replace the card assembly FIELD COIL CONNECTORS CONNECTION POINTS OF POWER CORD LEADS CHECK FIELD Using a continuity light or ohmmeter check the field by attaching one lead to each field coil connection Continuity should exist between these two points Check continuity between each field coil connection and the starter housing No continuity should exist ARMATURE CHECK Ifthe commutator bars are glazed or dirty they can be turned down on a lathe While rotating hold a strip of 00 sandpaper lightly on the commutator and moving it back and forth Do not use emery cloth Recut the grooves between the commutator bars to a depth equal to the width of the insulators Use a continuity tester to make certain no continuity exists between the commutator copper and the iron core of the armature rotate armature and check out all commutator bars The armature can be thoroughly checked with a growler if available TROUBLESHOOTING STARTERS STARTER DOES NOT FUNCTION Check for 1 No current to the starter caused by faulty connections or blown circuit breaker 2 Faulty safety switches ignition starter switch or solenoid 3 Engine locked up or parasitic load on engine 4 Shorted open or grounded field coil 5 Open shorted or bent armature 6 Brushes sticking or damaged 7 Dirty or oily brushes or commutato
76. nd equipment TUNE UP PROCEDURE The following is a minor tune up procedure Repair procedures for this engine and it s components are listed in this manual if the engine does not perform to satisfaction after tune up is performed CAUTION Remove spark plug wire before doing any service work on engine 1 Service or replace air cleaner as necessary NOTE Snow King engines do not use an air filter due to the clean operating environment and to prevent filter freeze up 2 Remove blower housing clean all dirt grass or debris from air intake screen cylinder cooling fins and carburetor governor levers and linkage 3 Remove carburetor clean and install a carburetor kit make adjustment presets where needed Presets are found in the carburetor section of this manual Make sure fuel tank fuel filters and fuel lines are clean Reinstall carburetor replacing any worn or damaged governor springs or linkage Make proper governor adjustment Adjustments are found in the manual under governor linkage and adjustment and engine reassembly 4 Replace the spark plug with a correct equivalent 5 Make sure all ignition wires are properly routed so they will not rub on flywheel Inspect all ignition wires for abrasion or damage Remove flywheel and check flywheel key reinstall flywheel torque flywheel nut to specifications Set air gap between solid state module and flywheel at 0125 Air gap gauge part no 670297 may be used
77. ne enters through openings around the shutter As the engine starts to rotate the downward piston travel will create a low air 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 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 At engine IDLE speed a relatively small amount of fuel is required to operate the engine The throttle is almost completely closed A fuel air mixture is supplied through the primary idle fuel discharge orifice during idle During INTERMEDIATE engine operation a second orifice is uncovered as the throttle shutter opens and more fuel mixture is allowed to atomize with the air flowing into the engine During HIGH SPEED engine operation the throttle shutter is opened Air flows through the carburetor at high speed The venturi which decreases the size of the air passage through the carburetor further accelerates the air flow This high speed movement of the air decreases the air pressure at the mai
78. ng from Tecumseh Products Company Training Department Manager IGNITION 2 22 2222222 2 ee ta 31 IGNITION OPERATION Pre 1985 Production sehr 31 MAGNETO IGNITION seen 31 CONTACT POINTS eene 31 CONDENSER diccionario 31 OPERATION OF THE TECUMSEH MAGNETO IGNITION A 31 SOLID STATE IGNITION 1985 to Present 32 SOLID STATE IGNITION OPERATION 32 IGNITION SERVICE eene 33 SPARK PLUG SERVICE AA 33 FLYWHEEL REMOVAL AND SERVICE 33 FLYWHEEL MAGNETS AAA 33 FLYWHEEL KEYS us an 34 ADAPTER KEY TO FLYWHEEL ASSEMBLY 34 FLYWHEEL SLEEVE 0 3 34 FLYWHEEL TORQUE eene 34 REPLACING MAGNETO BREAKER POINTS 34 CONDENSER CHECK A 34 IGNITION COIL en 34 IGNITION TIMING AAA 34 FIXED TIME SPEED EXTERNAL COIL 36 SOLID STATE CDI een 36 OTHER IGNITION SYSTEMS A 36 OUTBOARD TIMING eren 38 OUTBOARD TIMING STANDARD IGNITION 38 OUTBOARD TIMING SOLID STATE 39 CYLINDERS amp INTERNAL COMPONENTS 41 PISTON amp RING SERVICE a 41 CONNECTING ROD SERVICE 42 NEEDLE BEARINGS eee 42 CRANKSHAFT BEARING AND OIL SEAL SERVICE ran 43 NEEDLE BEARINGS eene 43 Page OIL E iicet arg 43 ONE PIECE SEALS eere 43 THREE PIECE SEALS em reete 44 OUTBOARD SEAL SERVICE
79. ngine versus every other stroke on 4 cycles 1 INTAKE AND IGNITION COMPRESSION OPERATION OF PISTON PORT STYLE 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 buildup 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 OPERATION OF REED PORTED STYLE WITH LOOP SCAVENGING The following illustrates the loop scavenge design which uses a vacuum pressure activated reed valve Here the ports are located on three sides of the cylinder the intake ports are on two sides opposite each other and the exhaust ports are illustrated by the three holes just above the head of the piston As the mixture flows into the combustion chamber through the transfer ports it collides and is directed to the top of the combustion chamber loop
80. nnecting rod onto the crankshaft journal place a few drops of oil onto the needle bearings and install rod cap Torque bolts to specification 42 CRANKSHAFT BEARING AND OIL SEAL SERVICE Check if crankshaft is bent or otherwise damaged Make certain keyways are not worn or damaged and flywheel taper is clean and in good condition Iftaper orkeyways are worn or damaged replace crankshaft Check oil seal contact surfaces on crankshaft for damage or scratches which would damage oil seal or cause leaks On engines that are equipped with ball bearings the crankshaft must be removed with the shroud base Before removing shroud base with crankshaft disassemble rod cap from rod and remove the piston from the bore then remove four 4 shroud base screws and tap shroud base so base and crankshaft can be removed together To remove crankshaft and bearing from shroud base use following procedure Using a propane torch heat the area of shroud base around the bearing area until there is enough expansion to remove the crankshaft and bearing HEAT AREA Fe o HEAT AREA SHROUD BASE To remove the bearing from crankshaft remove retainer ring if so equipped and use a bearing splitter to pull bearing Before installing bearing on crankshaft clean out the grooves on the crankshaft where bearing locates and put Loctite in the groove Models with the retainer ring do not require Loctite Using a sleeve over the crankshaft p
81. nt Remove when cleaning and replace with new seals DUST SEALS INLET FITTING A EESSSSN N N INLET NEEDLE Proper installation is important See N AND SEAT appropriate chapter for procedures 7S FEA SOFT BAFFLE PLUG NorIZIZZ FLOAT BOWL Replace re GASKET sume FLOAT SHAFT Clean with compressed air FUEL PICK UP INLET Must hook over float tab NEEDLE CLIP 9 IB ANY A Long straight end of clip must face the choke end of the carburetor la D EEN AA IL Clean with compressed air MAIN JET FLOAT EON and Suet fat level codo FLOAT BOWL gasket or gaskets BOWL NUT GASKET Set float to proper level NON METALLIC ITEMS CAN BE DAMAGED BY HARSH CARBURETOR CLEANERS Loosen screw until it just clears CHOKE SHAFT AND LEVER Check shaft for binding Position throttle lever then turn screw in 1 IDLE SPEED ADJUSTMENT SCREW shutter opening towards inlet fitting turn CHOKE SHUTTER side of air horn THROTTLE SHAFT AND LEVER Place detent reference mark to DETENT REFERENCE MARK proper location See chapter ON THROTTLE SHUTTER appropriate to specific carburetor THROTTLE SHUTTER Check spring for return action and THROTTLE SHAFT binding us RETURN SPRING INLET Primer bulb models have a Teflon FITTING one way valve in or behind the fitting
82. or and remove the float bowl Place a drop of an oil based product such as WD 40 on the tip of the needle valve Using a commercially available 0 30 psi pump and gauge attach the pumps hose to the carburetor inlet Apply approximately 6 psi or until the needle pops off the seat The needle should seat at 1 5 psi or greater for a minimum of 5 minutes Ifthe minimum 1 5 psi cannot be maintained for this period of time then service to the needle and seat is required 5 32 FLAT PUNCH DRIVE IN UNTIL SEAT SEAT RESTS ON BODY SHOULDER INSERT THIS _ FACEFIRST Se FLOAT HEIGHT SETTINGS Previously the float height was set by using a 670253A float setting tool The new float setting will require an 11 64 drill bit The procedure for setting the float height is as follows Remove the bowl gasket then hold the carburetor in the inverted position Place the drill bit across the carburetor body opposite and parallel to the float hinge pin Adjust the float height by bending the tab on the float until it touches the bit INLET NEEDLE SEATS AT THIS POINT If the required adjustment is minor the tab adjustment may be made without removing float and carefully inserting a small bladed screwdriver to bend the tab Be careful not to damage other parts The idle on the Series 8 is metered using a threaded restrictor See illustration Proper torque of this restrictor is critical it should be torqued to 5 8 in lbs or 5 to 1 nm o
83. orary knot and allow the rope to recoil HANDLE ASSY gt DOG SPRING N senio amp KEEPER y ASSY BRAKE SPRING d DOG RETAINER amp A RETAINER SCREW STARTER DOG EYELET VERTICAL PULL STARTER HORIZONTAL ENGAGEMENT TYPE DISASSEMBLY PROCEDURE 1 Remove the handle and relieve the starter spring tension by allowing the rope to slip past the rope clip Remove the spring cover by carefully removing the two small screws Carefully take out the spring Remove the center hub screw and the spring hub Lift off the gear and pulley assembly Disassemble the pulley assembly by removing the snap ring and washer diag 13 Remove the starter rope if necessary Replace all worn or damaged parts HANDLE ROPE CLIP Assembly Procedure 1 2 3 Insert the rope through the starter pulley Assemble the gear pulley washer and snap ring Place a small amount of grease on the center shaft place the gear and pulley into position making sure the brake spring loop is positioned over the metal tab on the bracket The rope clip must fit tightly onto the bracket The raised section fits into the hole in the bracket Install the hub and hub screw Torque the hub screw to 45 55 in lbs 5 6 Nm A loose hub screw will prevent the rope from retracting Install the return spring if necessary A replacement spring is installed by placing the spring and its retainer o
84. ost without moving it Tighten the lock screw to hold the cam in place 40 GROUND SCREW THROTTLE RUN ACTUATING LOCKING SCREWS BRACKET THROTTLE POST ai CONTROL LEVER Recheck to insure that the high speed point hasn t changed or that binding will not occur Readjust from the high speed point to the pickup point as necessary When assured that the cam position is correct at the FULL RUN and IDLE positions torque the lock screw to 10 15 in lbs CYLINDERS amp INTERNAL COMPONENTS PISTON amp RING SERVICE Before removing the piston clean all carbon from the cylinder making certain thatthe carbon ridge is removed from the top ofthe cylinder This will prevent ring damage when removing the piston Push the piston through the top of the cylinder using a wooden dowel on the inside of the piston so that the connecting rod and other parts will not be damaged Check the piston and cylinder for scoring or other damage Check the piston rings for wear by inserting them into the cylinder to about 1 2 inch from the top ofthe cylinder Check at various places to make sure that the gap between the ends of the ring do not exceed the dimensions indicated in the Table of Specifications Bore wear can be checked by the same method except use a new ring to measure the end gap IN RING len SCH TRAVEL AREA INVERTED PISTON TO POSITION RING SQUARELY IN CYLINDER CHECK RING END GAP Before insta
85. over the primary windings One end connects to the spark plug and the other end is grounded to the stator body The coil is used as a transformer to increase the primary voltage to a high voltage 10 000 20 000 volts which jumps across the spark plug gap SECONDARY LEAD PRIMARY LEAD SECONDARY PRIMARY GROUND PRIMARY LEAD WINDING GROUND LEAD TERMINAL FOR PRIMARY AND SECONDARY SECONDARY GROUND LEAD The actual connection of the primary and secondary ground is normally made inside of the coil but it is shown above to illustrate the individual wires CONTACT POINTS The contact points consist of an insulated movable point that connects to the coil primary lead and a stationary point that is grounded to the stator body which provides the return path for the primary circuit CONDENSER The condenser acts as an electrical shock absorber to prevent arcing between the contact points as they open Arcing lowers the voltage at the spark plug as well as burn and pit the contact points thus shortening point life OPERATION OF THE TECUMSEH MAGNETO IGNITION As the flywheel turns the magnets mounted in the wheel pass the coil mounted on the stator As the magnet s North Pole enters the area of the center leg ofthe stator a magnetic field is concentrated through the laminations to the magnet s South Pole This causes a generation of current flow in the coil s primary winding The ignition points are closed
86. r STARTER CRANKS ENGINE SLOWLY Check for 1 Parasitic load or tight engine 2 Worn brushes or weak brush springs 3 Dirty oily or worn commutator 4 Worn bearings in cap assemblies 5 Defective armature STARTER SPINS ENGINE DOES NOT CRANK Check for 1 Pinion gear sticking on shaft 2 Damaged pinion or flywheel ring gear 27 ALTERNATORS Some engines are equipped with an alternator and regulator to supply current to power head lights tail lights etc on recreation vehicles Shown here is a typical wiring diagram HEAD amp TAIL LIGHT STOP LIGHT MAGNETO GROUND MAGNETO GROUND LIGHT SWITCH TAIL STOP LIGHT HEAD LIGHT SIS x CHECKING THE SYSTEM At an idle speed 2600 R P M a slight dimming of the lights will be noticed This is normal and should not be considered faulty Before going into extensive checks be sure to examine the more basic causes first such as 1 Make sure bulbs are good and the right ones are being used Number 1157 for tail amp stop light 4416 or 4420 for head lights Corroded terminals Cracked wire insulation Broken wires Broken wires covered by insulation A wire grounding out the system Loose connections Ra vOv Be I9 Make sure regulator has good ground 9 Faulty Switch Check the regulator for resistance If regulator checks out and all bulbs and wiring are ok replace alternator coils Three types of regulators have been uti
87. r Ohmmeter indicates a break in the circuit At this point torque down the stator bolts and the timing procedure is completed Before putting the dust cover back on the points box clean the points by sliding lint free paper back and forth between the contacts Manually open the points when removing the paper to eliminate paper fibers from remaining between the contact points LINT FREE PAPER FIXED TIME SYSTEM External Coil This system has the contact points and condenser mounted under the flywheel with the laminations and coil mounted outside the flywheel This system is identified by the square hole in the stator the round configuration of the coil and a stepped flywheel key Begin the timing procedure torque down the stator bolts to secure the stator in place Next rotate the crankshaft until the point arm is resting on the high side of the ignition cam Set the point gap at to the proper specification by loosening the screw on the movable point and inserting a feeler gauge between the contact points Tighten the screw on the movable point and then recheck the point gap Be sure to clean the contact points with lint free paper Reinstall the proper flywheel key flywheel washer and torque down the flywheel nut to specification Reinstall the external coil but do not tighten down the mounting screws ROUND COIL STEPPED KEY STEPPED END f TOWARD ENGINE P FLYWHEEL SLEEVE Timing this system consists of ha
88. r it may vibrate loose When the restrictor is placed in the idle circuit passage it is capped with a tamper resistant plastic cap If the jet is removed for cleaning it must be recapped to prevent tampering when it is re installed IDLE RESTRICTOR The inlet needle hooks onto the float tab by means of a spring clip To prevent binding the long straight open end of the clip must face the choke end of the carburetor as shown THROTTLE END The float dampening spring on the HIGH TILT FLOAT STYLE carburetor has an extended end which must point toward the choke end of the carburetor POINTS TOWARD CHOKE END FLOAT DAMPENING SPRING PRIMER BULB To install start the retainer and bulb into the casting with the retainer tabs pointed out Firmly push the bulb and retainer into position using a 3 4 19mm deep well socket CLEANING CARBURETOR BODY When removing choke and throttle shafts check shafts and bearings in carburetor body for wear Any looseness in these areas can cause dirt to enter the engine resulting in premature wear If dust seals are present they should be positioned next to the carburetor body Install the dust seal metal washer and finally the return spring Welch plugs should be removed for proper cleaning ofthe carburetor See welch plug service atthe beginning of this section When all accessories and shafts have been removed soak the carburetor in carburetor cleaner for a maximum of 30 minutes Blow
89. rce to Remove INLET SEAT GASKET INLET FITTING INLET NEEDLE YS SEAT AND WA gt SPRIN ZN B UA SSS ASSEMBLY DIAPHRAGM GASKET DIAPHRAGM BLUE THREAD LOCK SEALANT APPLIED FIXED IDLE RESTRICTER JET FIXED MAIN JET ATMOSPHERIC VENT HOLE MAIN NOZZLE WITH CHECK BALL CHOKE SHAFT AND LEVER Check shaft for binding Position shutter opening towards inlet fitting CHOKE SHUTTER side of air horn HIGH SPEED AIR BLEED Remove and replace Primer bulb models have a Teflon one way valve in or behind the fitting Proper installation of assembly is important See appropriate chapter for procedures Gasket and diaphragm sequence may be reversed on some models Head of rivet must touch inlet needle Hole must be clean On models with primer bulb vent hole is very small and is located off center or in the primer bulb OUTBOARD CARBURETORS Carburetors on outboard applications use float type which have a separate idle speed fuel pickup tube pressed into the casting The idle mixture screw is located on the top of the carburetor near the engine This carburetor has been manufactured with 2 different types of inlet needle and seats One has a hard needle with a synthetic rubber seat the other has a non replaceable brass seat with a synthetic rubber tipped needle IDLE SPEED FUEL PICKUP Outboard carburetors have a built in fu
90. ress bearing into position with arbor press Make certain crankshaft counter weight is supported and bearing is pressed on inner race only RETAINER RING some Models po rU SUPPORT COUNTERWEIGHT BEARING To reinstall crankshaft and ball bearing heat shroud base to expand bearing seat and drop ball bearing into seat of base shroud Allow to cool On outboards only install shroud base onto cylinder but before tightening screws rotate shroud base fully clockwise Tighten screws If a ball bearing engine appears to be tight or if the flywheel was removed with the use of a knock off tool the ball bearing may be dislodged from shroud base forcing the crankshaft lower thrust face against the cylinder thrust face To correct this condition rap sharply on the P T O end of the crankshaft with rawhide mallet to provide the clearance between the crankshaft and cylinder thrust face BALL BEARING MUST HAVE CLEARANCE NEEDLE BEARINGS Caged needle bearings can be removed and replaced by pressing them in and out of cylinder using an arbor press NOTE Always press against the lettered side of the bearing If the needles fall out of the cage they can be reinstalled using grease to hold them in position OIL SEALS It is important on 2 cycle engines that oil seals are in good condition A leaky seal will cause hard starting erratic running and possible damage to internal components due to a lean fuel oil mixture
91. rnal moving parts for lubrication AIR CLEANERS CARBURETORS GOVERNORS AND LINKAGE AIR CLEANERS Service the air cleaner frequently to prevent clogging ofthe cleaner and to prevent dust and dirt from entering the engine Dust bypassing an improper or damaged air filter can quickly damage an engine Always make certain covers and air cleaner connections are tightly sealed to prevent entry of dirt NOTE Snow King models do not use air cleaners due to the clean environment that they operate in and also to prevent air cleaner freeze up When excessive carburetor adjustment or loss of power results inspect the air filter for clogging NOTE Use factory recommended parts only POLYURETHANE TYPE AIR CLEANER These serviceable air cleaners utilize a polyurethane element which will clog up with use The element should be cleaned and serviced in the following manner Wash element in a detergent and water solution and squeeze don t twist until all dirt is removed Rinse thoroughly Wrap in clean cloth and squeeze don t twist until completely dry Clean air cleaner housing and cover Dry thoroughly Re oil element by applying generous quantity of oil to all sides Squeeze vigorously to distribute oil and to remove excess oil S A E 30 When reassembling polyurethane oval type air cleaners place cupped screen into housing with edge against carburetor end of housing Screen should be installed to hold element away from ho
92. rnor if present STANDARD SERVICE CARBURETORS FUEL FITTING NOTE MOST service carburetors are marked SVC CARB NP in the Price List This means that the carburetor comes with NO FUEL FITTING Use the parts manual to obtain the same fuel inlet fitting that was installed in the original carburetor Install the fuel fitting in the new carburetor body in the same position as on the original carburetor Support the carburetor body with a wood block to avoid damage to other parts Use a bench vise or press to install the fitting squarely Press it in until it bottoms out NOTE PRESS FUEL FITTING IN SQUARELY USING CAUTION SO THAT THE CARBURETOR BODY IS NOT DAMAGED INLET FUEL FITTING To remove a leaking or damaged fuel inlet fitting use a 1 4 6 mm bolt 1 4 6 mm nut and 1 4 6 mm washer along with a 1 2 12 mm nut Use a pliers or vise to remove the plastic part of the inlet fitting Tap the inside of the remaining metal portion of the fitting using a 1 4 20 6 mm tap Place a 1 2 12 mm nut over the fuel fitting it may be necessary to guide one side of the nut to seat it squarely to the carburetor Next thread the 1 4 6 mm nut on the bolt until it contacts the shank add the washer and thread the bolt into the fitting until snug Tighten the 1 4 20 6 mm nut until the fitting is removed CHOKE SHAFT NOTE Never reuse choke or throttle shutter screws always replace with new Tecumseh service screws pa
93. rst method was used until the mid 1980 s using the base model number with a type number The type number was used to identify variations for the OEM s specific needs The second method was put in place to standardize 2 cycle and 4 cycle engine identification The type number has now become the specification number which is preceded by the engine model Example AV520 Tecumseh type numbers are stamped into the blower housing or are located on a nameplate or tag on the engine Model and Specification numbers are either stamped into the blower housing or located on a decal on the side of the blower housing Column Column Column TYPE NO No TYPE NO No TYPE NO No Vertical Crankshaft Engines Horizontal Crankshaft Engines Horizontal Crankshaft Engines 638 thru 638 100 639 thru 639 13A 640 02 thru 640 06B 21 640 07 thru 640 21 A 640 23 641 thru 641 14 642 01 A 9A 642 02 A thru G 642 02E F 642 03 A B 642 04 A B C 642 05 A B 642 06 A 642 07 A B 642 07C 642 08 642 08A B C 642 09 thru 642 14 642 13 thru 14C 642 15 thru 642 23 642 24 thru 642 33 642 35 643 01 A 03 A 643 03B C 643 04 05A 643 05B 643 13 14 643 14A B C 643 15 643 15A thru 643 32 643 32A 643 33 643 34 643 35 A B 650 653 01 thru 653 05 653 07 thru 653 10 660 11 thru 660 38 660 39 A 660 40 661 01 thru 661 29 661 30 thru 661 45 662 02 662 623A 42 670 01 thru 670 109 1398 thru 1399 1400 1401 thru 1401F 1401G
94. rt number 650506 Remove the choke shutter screw from the original carburetor and remove the choke shaft Observe the position of the ends of the choke return spring if one is present Also observe the position of the cut out and or holes in choke shutter Some chokes turn clockwise and some turn counterclockwise note the position of the choke shaft prior to removal from the old carburetor If a choke stop spring is present on the new carburetor and is not used on the old carburetor cut it off with a side cutter or pull it out using a pliers Test the action of choke shaft to make sure it moves freely and easily and does not bind in either open or closed position If binding occurs loosen the shutter screw reposition the shutter and tighten the screw THROTTLE LEVER Remove the throttle lever and spring and file off the peened end of the throttle shaft until the lever can be removed Install the throttle spring and lever on the new carburetor with the self tapping screw furnished If dust seals are furnished install them under the return spring IDLE SPEED ADJUSTMENT SCREW Remove the screw assembly from the original carburetor and install it in the new carburetor Turn it in until it contacts the throttle lever Then an additional 1 turn for a static setting FLOAT TYPE CARBURETOR CHOKE SHAFT N _ SELF TAPPING SCREW LEVER bi IDLE CRACK ae SCREW AND ES SPRING Q g SPRING SPRING WASHER WASHER
95. set points per specification and set air gap between flywheel magnets and laminations to 005 to 008 Air gap gauge part number 670216 which measures 0075 may be used Use Loctite 242 Blue on screws and torque down mounting screws to specification Remove air gap gauge MAGNETS AIR GAP DIMENSION 005 37 OUTBOARD TIMING OUTBOARD TIMING STANDARD IGNITION Follow the step by step procedure outlined for timing outboard engines with Standard ignition magnetos non solid state Apply a small amount of E P Lithium grease to the contact area of the friction screw Do not turn the screw into the radius of the stator collar CONTACT AREA OF FRICTION SCREW Install the stator with operating handle pointed in the direction of the carburetor Be sure the throttle post is NOT INSIDE the arc of the throttle actuating cam Hold the throttle open when installing the stator THROTTLE ACTUATING CAM Ur CONTROL LEVER THROTTLE POST Move the control lever to full retard then move toward full advance while tightening the friction screw until the lever will not vibrate out of position when the engine is running and yet can be easily rotated when speed is adjusted FRICTION SCREW 38 Adjust ignition points to proper specification Clean points by sliding lint free paper back and forth between the contacts Manually open points when removing paper to eliminate paper fiber from remainin
96. the screw on the side of the adaptor sleeve to allow the sleeve to be turned into the threads of the spark plug hole not the entire dial indicator This will ensure the proper location of the tip Once the adapter sleeve is secured in the hole tighten screw on sleeve adaptor to prevent the dial from moving up or down which would give a false reading Find top dead center TDC by rotating the crankshaft clockwise when looking at the magneto end of the crank until the needle on the dial stops and reverses direction Where the needle stops is TDC Loosen the screw on the dial and rotate the dial so that zero is lined up with the needle at TDC Tighten the screw on the dial to secure it in place DIAL SCREW DIAL AT O While watching the needle on the dial indicator rotate the crankshaft counterclockwise when looking at the magneto end of the crank past the specified Before Top Dead Center BTDC dimension Then rotate the crankshaft back clockwise to the proper dimension this will take out any slack between the connecting rod and crankshaft assembly Using 080 2 0 mm BTDC dimension as an example Next disconnect the leads from the point terminal and be sure to reinstall the securing nut amp tighten it up Connect one lead of a continuity light or Ohmmeter to the point terminal and the other lead to a good ground Loosen the two bolts holding down the stator and rotate the stator until the continuity light o
97. turn the screw counterclockwise until the engine start to sputter or drops in R P M remember this location Now turn the screw clockwise until it is halfway between these two locations This will be the optimum carburetor setting DIAPHRAGM SINGLE AND DUAL ADJUSTMENT Turn the mixture adjustment screw s clockwise finger tight then one 1 turn counterclockwise This setting will allow the engine to be started so that the carburetor can be fine tuned Do not adjust the carburetor when the engine is cold Start the engine and let it warm up for approximately 5 minutes If the engine falters or stops after the choke lever is moved to the OFF position turn the adjusting screw 1 4 turn counterclockwise and restart the engine NOTE On dual adjust the first adjustment must be made with the main mixture screw With the engine running turn the mixture adjustment screw clockwise until the engine starts to falter remember this location Next turn the screw counterclockwise until the engine starts to sputter or drop in R P M remember this location Now turn the screw clockwise until it is halfway between these two locations This will be the optimum carburetor setting With dual adjust carburetor repeat the above steps for the second idle mixture adjusting screw SERIES IDLE MIXTURE SCREW MAIN MIXTURE SERIES III IV IDLE MIXTURE SCREW MAIN MIXTURE DIAPHRAGM E DESIGNATION Ly WA a mcs MAIN MIXTURE SC
98. uld always be transferred to a new short block for correct parts identification THIS SYMBOL POINTS OUT IMPORTANT SAFETY INSTRUCTIONS WHICH IF NOT FOLLOWED COULD ENDANGER THE PERSONAL SAFETY OF YOURSELF AND OTHERS FOLLOW ALL INSTRUCTIONS ENGINE FUEL MIX U S U S METRIC Amount of Oil To Be Added 5 3 OZ 10 7 oz METRIC Amount of Oil To Be Added 167 ml 333 ml Petrol 4 Liters 8 Liters Gasoline 1 Gallon 2 Gallons 1 Gallon 2 Gallons 125 ml 250 ml 4 Liters 8 Liters 4 oz 8 oz 1 Gallon 2 Gallons 2 5 Oz 5 0 oz 80 ml 160 ml 4 Liters 8 Liters FUELS 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 carbon deposits Premium gas or gasohol containing no more than 10 ethanol can be used if unleaded fuel is not available NOTE NEVER USE GASOLINE CONTAINING METHANOL GASOHOL CONTAINING MORE THAN 10 ETHANOL UNLEADED REGULAR GASOLINE CONTAINING MORE THAN 15 M T B E OR ETBE GASOLINE ADDITIVES OR WHITE GAS BECAUSE ENGINE FUEL SYSTEM DAMAGE COULD RESULT NOTE In countries where unleaded gasoline is not available regular gas can be used Make sure that gasoline and oil are stored in clean covered rust free containers Dirt in fuel can clog small ports and passages in the carburetor Us
99. using to allow full utilization of air cleaner element NOTE Polyurethane type filters will lose effectiveness if stored for extended periods of time due to oil migration settling Down through the filter Re oil filter as necessary CUPPED SCREEN MUST BE POSITIONED WITH EDGES AWAY FROM ELEMENT ELEMENT FLOCKED SCREEN KLEEN AIRE SYSTEM This system uses a polyurethane type element Service as described under polyurethane type air cleaner When removing air cleaner body from carburetor remove plug in the body to gain access to the mounting screw Make certain plug is put back in place If it shows damage replace POLYURETHANE ELEMENT PLUG MUST BE IN PLACE FLOCKED SCREEN PAPER TYPE AIR CLEANER SERVICE Replace air filter once a year or more often in extremely dusty or dirty conditions DO NOT ATTEMPT TO CLEAN OR OIL PAPER TYPE FILTER Be sure to clean base and cover thoroughly before installing new paper filter NEVER RUN THE ENGINE WITHOUT THE COMPLETE AIR CLEANER INSTALLED ON THE ENGINE NOTE Serious damage to the engine may result in using any other but the specified part number filter Use factory recommended parts only GENERAL CARBURETOR INFORMATION CARBURETOR IDENTIFICATION Tecumseh carburetors are identified by a manufacturing number and code date stamped on the carburetor as illustrated ALTERNATE LOCATION FOR MANUFACTURING NUMBER CARBURETOR CARBURETOR CODE DATE MANUFACTUR
100. ver the top of the pulley and pushing the spring out of the retainer into the pulley s recessed area Install the spring cover and the cover screws Wind the rope onto the pulley by slipping it past the rope clip When the rope is fully wound on the pulley wind the pulley assembly two additional turns to put tension on the spring Mount the starter on the engine making sure the top of the starter gear teeth are no closer than 1 16 1 59 mm from the top of the flywheel ring gear teeth MOUNTING BRACKET TAB MUST FIT INTO SPRING LOOP RECEPTACLE FOR RAISED SECTION ROPE CLIP STYLIZED REWIND STARTER WITH PLASTIC RETAINER DISASSEMBLY PROCEDURE 1 After removing the rewind assembly from the engine blower housing remove the starter handle by first pulling a length of rope out using the handle tying a temporary knot in the exposed rope and either untying the knot in handle or prying out the staple Untie the temporary knot and slowly allow the rope to fully retract into the starter housing and the recoil spring to fully unwind Remove the decal from the center of the starter housing Use a small Phillips screwdriver or similar tool to pry the retainer legs apart and lift out the retaining wedge Pinch the legs of the retainer together and pull on the head of the retainer to remove it from the housing Remove the pulley assembly from the recoil housing Repair or replace as necessary RETAINER WEDGE
101. ving the proper 0125 317 mm air gap gauge Part No 670297 between the magnets and laminations and torque down the mounting screws to specification Remove air gap gauge and rotate flywheel to check for any possible striking points If none are found the air gap is set correctly and the timing procedure is completed SOLID STATE CDI This is an all electronic ignition System with the components sealed in a module and located outside the flywheel A Solid State module can be identified by its square configuration which will identify the need for the proper flywheel key or sleeve FLYWHEEL SLEEVE SQUARE MODULE The proper air gap setting between the flywheel magnets and the laminations on both the fixed time and CDI systems is 0125 Place 0125 gauge part No 670297 between the magnets and laminations and torque down mounting screws to specification Recheck gap setting to make certain there is proper clearance between the magnets and laminations NOTE Due to variations between pole shoes air gap may vary from 005 020 when flywheel is rotated There is no further timing adjustment on external lamination systems SQUARE MODULE OTHER IGNITION SYSTEMS Ignition systems on engines with a non adjustable stator set the points per specification If the coil is located under the flywheel no other timing is required SET GAP PER SPECIFICATION If engine has the coil and lamination outside of flywheel
102. will not leak A leaking gasket will cause erratic running hard starting and could damage internal components by causing an imbalance of fuel oil air mixture REED VALVES Make sure reeds and sealing surfaces are free of dirt and foreign matter Check reeds for seal against sealing surface of the adapter Reeds should not bend away from sealing surface more than 010 254 mm If the reeds are serviceable the smooth side of the reed must locate against the sealing surface Service reeds have smudge marks on smooth side If these marks are gone feel for a rough edge and assemble away from sealing surface AUTOMATIC COMPRESSION RELEASE DOUBLE REED TYPE Cranking compression pressures bleed past reeds and into muffler Once the engine is started a high pressure build up between the reeds forces the reeds against their seats stopping compression bleed off and allowing engine to run at full compression CYLINDER REED COVER REED TYPE Replace both reeds If either is defective When installing reeds be sure the colored side of the reed faces its seating surface If in doubt feel for a rough edge on the reed The rough edge must be installed away from the seating surface Assemble reed stop and hold down and tighten self tapping screws Poor running or lack of power may be caused by a leaking reed or cover gasket AUTOMATIC COMPRESSION RELEASE SINGLE REED TYPE Cranking compression pressures bleed past

TECUMSEH - 2-CYCLE ENGINES

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