o - FarmallCub.com
Contents
1. FUEL SUPPLY SYSTEM IDLING SYSTEM LOAD SYSTEM STARTING SYSTEM Fuel Supply System The fuel supply system is that portion of the carburetor consisting of the fuel in let strainer fuel needle valve and seat fuel float fuel bowl and the bowl air vent The function of the float and fuel needle valve is to maintain an even level of fuel in the bowl The float assembly consists of one or two float bodies soldered to a float lever This assembly hinges on the float axle supported by a bracket on the bowl cover Fuel from the supply tank enters the bowl through the inlet strainer and the float needle valve As the level of fuel rises in the bowl the float is carried upward until the float lever forces the needle valve against its seat stopping further inflow of fuel While the engine is in operation fuel flows from the bowl through the main metering jet to the load system or idling system and the float valve maintains just enough opening to sustain a constant level of fuel in the bowl The bowl air vent passage is a drilling in the throttle body connecting the float chamber with an air vent channel surround ing the venturi Air for the bowl vent the well bleed and the idling system is taken from this channel in the venturi which in turn is vented to the carburetor main air intake In this manner all air taken into the carburetor is supplied through the air cleaner This not only prevents entry of2. Adjust the ball joint until the handle is within 3 4 inch of the stop as shown HO Engine speed J control lever Engine speed contro lever lust 32 Adjustments to correct engine speed control lever position International 560 tractors 34 lower rod until the governor control bellcrank is in position 9 32 shown in Ilust 30 d Adjust the ball joint on the gov ernor control upper rod until the upper edge of the operator s speed control lever is within 5 16 inch of the upper stop on the sector See Illust 31 After adjustments are completed con nect the governor control upper and lower rods and governor control balance spring International 560 Tractor To correctly position the operator s engine speed control lever proceed as follows a Set the governor at low idle by moving governor rockshaft le ver to vertical position to hold carburetor throttle closed Adjust the turnbuckle until the bellerank is in the position 13 16 inch shown Turnbuckle Governor control bellerank B 12021 O againstits stop screw This governor position must be held until adjustments are complet ed b Disconnect the governor con trol balancing spring and the governor control rod Adjust turnbuckle Illust 32 until the governor control bellcrank is in position 13 16 shown c Disconnect the governor con trol connecting rod Adjust the ball joint
3. affecting engine idling and governor action Throttle Plate The throttle plate should be inspected for burrs or damaged edges which would 11 prevent good contact with the throttle body bore when fully closed Never usea buffing wheel or wire brush to clean this plate its sharp edges must not be deformed l When installing the throttle plate in sert it into the shaft from the top of the throttle body with the short end of the plate A down measured from the holes Insert screws from the top but do not tighten until the throttle plate is centered in the body bore Unscrew the throttle stop screw until the plate is allowed to close fully Holding the shaft lightly in the closed position tap lightly on the face of the throttle plate with a brass rod to jar it into a centered posi tion The screws may then be tightened The throttle plate must fit the bore close ly with a minimum of light showing around its edges The throttle shaft must be per fectly free to turn without binding at any point Clinch over the exposed end of the throttle plate screws to lock them in place This can be done by clamping a 1 4 inch square rod vertically in a vise and locat ing the throttle body on the rod through the venturi to bring the end of the rod directly under the end of each of the throttle screws in turn A flat end punch can then be tappedagainst the outer end of the screw This must be done with care to preven
4. dirt and abrasives but creates what is called a balanced vent The ratio of air and fuel mixture from a balanced carburetor will not be seri ously affected by changes in condition of the air cleaner as it becomes restricted by accumulation of dirt A balanced type carburetor must have an airtight seal between the bowl and the bowl cover since any air admitted into the bowl other than through the calibrated vent will upset the ratio of air fuel delivery and also allow entry of dirt In review sustained constant level of fuel in the bowl together with control led venting of the bowl insures a stable supply of fuel to the various metering systems and is unaffected by the height of fuel in the supply tank or normal oper ating changes in air cleaner condition Idling System The idling system consists of 5 idle discharge port Illust 1 19 idle adjust ing needle 7 idle jet and the connecting channels and 6 air bleed This system controls the mixture at partially opened throttle for idle and slow engine speeds until the throttle is opened sufficiently to allow the load system to function Fuel for the idling system enters the 15 well through the 11 main metering jet and is drawn through the 7 idle jet calibration into the idle passage where it is mixed with air from the 6 idle air bleed Illust 1 The air fuel mixture enters the air stream past the throttle plate from the 5 idle discharge
5. now can save him probable trouble and expense later A busy shop can be more efficient and a better place to work A 45863 SPECIFICATIONS Tractor Series Engine Series Carburetor Gasoline Model IH 3 4 ZTH 68X7 ZTH 68X7 Part number 364 579 BOL 366 462 R92 367 822 R91 Liquid level 9 16 1 2 1 2 Float height 1 7 16 1 5 32 1 5 32 Float drop 1 5 8 Main metering jet 032 No 20L No 21 Idle jet 75 No 11S No 118 Discharge nozzle 39 __ 45 50 Venturi 15 15 16 Needle valve seat Air Cleaner Type 92 35 35 Oil bath Oil bath Oil bath One piece One piece One piece None None None Manifold Gasoline Type Heat control Control spring wind Governor Variable Speed Engine rpm Low idle 25 Fast idle 25 Rated load 10 The carburetor part number is stamped on a metal disc riveted to the throttle body This number identifies the calibration for fuel flow for a given tractor model and must be used when selecting replacement parts to maintain desired air fuel ratio Measurements are made from the machined face of the fuel bowl cover to the liquid level or to bottom of float assembly See Tllusts 7 8 and 9 SPECIFICATIONS 660 C 263 ZTH 68X7 IH 1 1 4 IH 1 1 4 IH 1 3 8 367 700 R91 367 258 R91 367 259 R91 372 723 R91 1 2 9 16 9 16 9 16 1 5 32 1 5 16 1 5 16 1 5 16 1 15 16 1 15 1
6. LEVEL a usi GASKET a IN PLACE y A 10442 Illust 8 Float measurements and liquid level Zenith 68X7 carburetor 140 240 and 340 series C 123 and C 135 engines BEND To ADJUST FLOAT eer b 3 LA rr 15 s TX Sir N W HEIGHT OF 7 FLOAT FROM A 681 A A UPPER BODY Ilust 9 Float measurements and liquid level IH 1 1 4 1 3 8 carburetors 460 560 and 660 series N C 221 and C 263 engines C yi Adjusting Screws and Seats The idle adjusting needle point must be smooth and free from grooves caused by being clos d forcibly against its seat Where this condition is found a new screw should be used The main jet adjusting screw where used and seat should be inspected for damage caused by the screw having been forced against its seat Where evidence of this is found both the screw and seat should be replaced Service tool Number HC 80 is used to remove the main adjust ing screw seat The old seat must not in any case be reinstalled since the removal operation will destroy the tapered seatand the calibrated opening The opposite end of the Number HC 80 tool is used to drive the new adjusting screw seat into place in the carburetor bowl casting see Illust 10 Venturi and Jets Inspect the venturi jets main adjust ing screw seat and other calibrated open ings for possible damage from improper probing in previous cleaning operations Use the carburetor identi
7. NK Air Vent pk A FNN a e ATT EIS egi dd dz VA E E gArrO GEA KE NU A 17 16 VA Sk EEE A d Q A 55090 Illust 1 Cross section of a typical carburetor with identification of the principal parts 1 Choke valve 7 Idle jet 12 Main jet adjustment screw 2 Venturi 8 Needle valve and seat 13 Well air bleed 3 Throttle plate 9 Liquid level 14 Idle adjusting needle 4 Throttle stop screw 10 Float assembly 15 Metering well 5 Idle ports 11 Main metering jet 16 Drip hole filler 6 Idle air bleed 17 Discharge nozzle re A Bleed holes in discharge nozzle Principal Parts The principal parts of a typical carbu retor are shown in Illust 1 Carburetor Operation l The function of the carburetor is to meter the required amount of fuel to meet varying demands of engine load and speed and to discharge this fuel into the intake air stream in as fine a spray as possible The air fuel ratio is not constant for all loads and speeds Idle and low speeds require rich fuel mixture full load full speed operation requires the leanest fuel mixture These modern carburetors with their air bleed well method of compensa tion will give these proportionate air fuel mixtures to meet load speed demands resulting in smooth economical engine performance To simplify the explanation of how the carburetor functions we will divide it into four systems and discuss each separately
8. a part of each engine tune up or major engine overhaul A small air leak which would allow the engine to draw in unfiltered dirty air will result in rapid engine wear and early failure A partly plugged air cleaner has a throttling effect on the engine resulting in loss of power and lowered fuel economy These con ditions would have a bad effect on an otherwise satisfactory tune up or overhaul job The use of heavier oil than recommend ed for the season of use in the air cleaner will also result in a throttling effect simi lar to a plugged cleaner Too heavy an oil in the air cleaner presents a problem in cold weather starting of the engine since it limits the available air fuel mix ture The use of too light an oil viscosity for the season of use will result in some f carry over of oil into the engine This leaves too low an oil level in the cleaner cup to provide good air filtration 2 MANIFOLD AND EXHAUST SYSTEM EL E KO A 49496 Ilust 18 C 135 engine manifold with vertically mounted exhaust muffler the C 60 and C 123 are similar EE The exhaust and intake manifolds for the C 60 C 123 and C 135 gasoline burn ing engines are combined in a single cast ing A small area located at the top of the intake riser is heated from the exhaust gases which assists in vaporizing the droplets of fuel without adding materially to the temperature of the air fuel mixture The exhaust
9. and intake manifolds for the C 221 and C 263 gasoline burning en gines are of two piece construction The intake manifold riser is jacketed for cir culation of exhaust gases to assist in va porization of fuel A thermostatically con trolled valve allows circulation of hot si exhaust gases to the intake jacket during i engine warm up period As the manifold approaches a normal operating tempera ture the thermostat closes the control valve reducing the heat applied to the intake jacket The control valve is coun ter balanced and must move freely in its mounting to be actuated by the bimetal thermostat spring At room temperature the thermostat spring will be wound 1 4 to 1 2 turn when hooked to its anchor pin and with the control valve open With extended use the heat control valve parts may burn and blister and tend to become inoperative Should the valve stick open some loss of power and econ omy will be experienced due to application of excessive heat to the intake manifold Should the valve stay in the closed position the lack of heat on the intake manifold will cause slow warm up and require extended use of the choke valve Extended use of either the one piece or two piece manifolds may result in carbon or coke like deposits in the heated area of the intake manifold Such deposits act as an insulator preventing the transfer lilust 19 C 221 and C 263 engine manifold showing con s
10. be re quired in each case This may have been found necessary in order to contact the maximum speed stop at one extreme or to contact the throttle lever stop screw at the other extreme After both fast idle and low idle speed adjustments have been completed it is suggested that both extremes of speed be rechecked with the service tachometer to be sure that the operators control is cap able of moving the system into contact with both stop adjustments Failure to at tain either stop with engine running would require readjustment of linkage Where considerable lost motion in the linkage has occurred because of wear the worn parts must be replaced to restore a full range of movement to governor speed change lever Loose brackets which act as supports for linkage levers and bellcranks will also re sult in lost motion and failure to secure full range of engine speeds Da ea Eak A AR Engine speed control lever DS N KEA Engine speed N bia control lever x x shaft NL x N NON N N Adjust the ball joint until the engine speed control lever is within 5 16 of the stop as shown Govemor control bellerank Govemor control lower rod Governor contro rod operating lever Adjust the tumbuckle until the lever is in the position 13 16 inch shown Side view B 12020A A control a WZ rod a Govemor control upper rod Governor contr gt EEE upper rod Governor control b
11. follows b With engine running and accurate service tachometer in use ad a Before adjustment is attempted vance operator s engine speed the engine must be brought up to control lever to maximum BUTTERFLY SHOULD BE IN WIDE OPEN POSITION IMPORTANT WHEN SPEED CHANGE LEVER 8 S PULLED BACK ADJUSTMENT MADE WITH TURNBUCKLE CIO GOVERNOR MECHANISM MUST BE ABSOLUTELY FREE WITH NO LOW IDLE FUEL MIXTURE BINDING AT ANY POINT ADJUSTING SCREW 8 SPEED CHANGE SE LEVER A a d TO REPLACE GOVERNOR SPRING QO 14 REMOVE GOVERNOR 7 HIGH SPEED ADJUSTING SCREW GOVERNOR HOUSING FELT SEAL Seri AG OILITE BUSHING ASS Ed 3 ROCKSHAFT MUST SPRING HOUSING FROM ENGINE zr THEN TAKE SPRING LEVER FROM SPEED CONTROL BE FREE WITH NO DRAG AT OIL SEAL PORTION OF p GOVERNOR n MAGNETO 9 HOUSING DRIVE GEAR gi EO Ss gak 4 3 erd BUMPER O a ze SPRING FOR ELIMINATING lt 7 NEEDLE BEARIN SURGE SCREW UP ENOUGH E HOUSING AT THIS JUST TO REMOVE SURGE IF SCREWED UP TO FAR IT WILL Se INCREASE IDLE SPEED OF ENGINE A 650 _ Ilust 29 Schematic drawing of C 123 and C 135 engine governor Assemble governor spring as shown using hole A ow in rockshaft lever Ci 30 O speed position Be sure also that operator s speed change linkage is being held firmly a gainst the governor maximum speed stop adjustment reset linkage if necessary c Adjust the governor maximum sp
12. in closed position Governors on the four cylinder engines are equipped with an ad justable bumper spring to counteract the effect of manifold vacuum on the closed position of the throttle Causes for binding or sticking of the throttle shaft are misalignment due to wear or interference due to inrproper as sembly Excessive tension adjustment of bumper spring in an attempt to overcome these ills will prevent the throttle from closing against its stop resulting in great LOW IDLE WIDE OPEN FAST IDLE er than specified low idle speed See car buretor Inspection and Repair portion of this manual section Low idle speed adjustment for all engines a b c d e Start engine and allow it to reach operating temperature Place operator s speed change lever in the extreme low speed position See that operator s speed change lever linkage will allow the throttle to close against its stop screw Adjust speed change linkage if necessary See also that governor bumper spring adjustment is not interfering with viously under carburetor and governor headings Bumper Spring Adjustment C 60 C 123 and C 135 engine governors only may be turned in one half turn at a time just sufficient to reduce surging to normal Test as in operation e above after each slight ad justment If screwed in too far the bumper spring will prevent the throttle from closing to low idle st
13. in the 15 well and 17 discharge noz zle is similar to the level in the fuel bowl As the load system goes into operation with increased load and throttle opening the fuel is drawn from the discharge noz zle at a higher rate than supplied to the 15 well by the 11 main metering jet This lowers the level of fuel in the 15 well As the load and throttle opening is increased the fuel level in the 15 me tering well drops below a series of A air bleed holes in the discharge nozzle admitting an increasing amount of air from the 13 well air bleed lust 1 This metered addition of air to the discharge nozzle is necessary to compensate for the fact that the partial vacuum produced at the nozzle increases out of proportion with the increased velocity of air through the venturi Were it not for this well air bleed compensation the proportion of fuel to air would rapidly increase with the throttle opening producing an extremely rich mixture at full throttle full load operation A small additional amount of fuel is necessary to insure prompt response for engine acceleration When the throttle is suddenly opened the resulting rush of air through the venturi picks up this necessary extra fuel which remains above the 11 e main metering jet in the 15 metering well Oy during part throttle operation f Carburetors on the C 221 and C 263 gasoline burning engines are equipped with a 12 main jet adjustment screw Illust
14. on the governor con trol connecting rod until the up per edge of the operator s speed control lever is within 3 4 inch of the upper stop on the sector Iliust 32 After the adjustments are completed con nect the governor control rod and the governor control con necting rod Replace the con trol balancing spring To prevent creeping of operator s en gine speed control lever more tension may be placed on the friction surfaces by tightening the adjusting nut which holds the operator s lever to its shaft Illusts 31 and 32 Be sure that friction surfaces are free from grease or oil Replace worn control lever friction disc when ad justment will not correct creeping Re place balancing spring if damaged or weak Where a service dynamometer is available a very good final check of gov ernor operation may be made After ad justment 1 Sychronizing the Governor to Carburetor Throttle Movement pro ceed as follows a Attach dynamometer start en yn gine and place under load for at 35 least 30 minutes to normalize operating temperatures of en gine oil air cleaner oil fuel and transmission lubricant b Disengage power take off use accurate service tachometer and check fast idle speed This must be within the specified range correct if necessary Check for governor surge as outlined under adjustment 3 Low Idle Speed paragraph e c Re engage power take off ad vance operator s speed control le
15. port The idle air adjusting screws on the carbu retors of C 60 C 123 and C 135 engines are turned toward their seat to enrich the air fuel mixture This adjustment is re verse on carburetors of C 221 and C 263 engines represented in Ilust 1 since these adjusting screws control the volume of air fuel mixture Load System The load system consists of the 2 venturi 17 discharge nozzle 15 well 13 well air bleed and 11 main metering jet The load system as the name implies controls the air fuel mixture during the time the engine is loaded or is operating above idle speed When the throttle plate is opened a short distance beyond the 5 idle port Ilust 1 a sufficient amount and velocity of air passes the 2 venturi and the 17 discharge nozzle to draw fuel from this source This condition starts the load system function ing Within a partial load speed range of throttle plate movement both the idling system and load system are delivering fuel Further opening of the throttle plate due to increased engine load speed results in diminished delivery of fuel from the idling system Ultimately all delivery of fuel from the idling system is stopped and air is being drawn from this source into the 15 well The 11 main metering jet has a cali brated opening large enough to permit the flow of the maximum amount of fuel neces sary for full load operation When the engine is stopped or idling the level of fuel
16. 1 which may be used to limit the amount of fuel going into the engine when under light load conditions Some increase in fuel economy can be obtained for periods of light load operation in this manner How ever when heavy work is to be performed in which the FULL POWER of the engine IS REQUIRED the fuel adjusting screw must be set five turns off its seat The 11 main metering jet in the carburetor has been calibrated to provide an economical full power mixture and must not be re stricted by use of the adjusting screw when full power of the engine is required Starting System The starting system consists of a man ually operated choke valve mounted in the Ch carburetor main air intake When the 1 choke valve plate Illust 1 is turned to the closed position it restricts the air entering the carburetor It does not how ever restrict the main air vent passage This upsets the balance of the carburetor allowing the increased suction to draw strongly upon the fuel discharge openings when starting the engine When the outside air manifold and engine combustion chambers are cold it is necessary to supply a very rich start ing mixture Only the lighter ends or more volatile portions of the fuel can be vaporized because of the low temperature and the slow movement of air past the dis charge nozzle due to low cranking speed The necessary large quantity of fuel is supplied by closing the choke valve during
17. 6 1 15 16 No 25L O Oil bath Oil bath Oil bath Oil bath One piece Two piece Two piece Two piece None automatic automatic automatic 1 4 1 2 turn 1 4 1 2 turn 1 4 1 2 turn 425 425 425 425 2200 1980 i 1980 2640 2000 1800 1800 2400 GENERAL DESCRIPTION The fuel system consists basically of a fuel supply tank fuel shut off valve fuel strainer carburetor intake exhaust mani fold air cleaner and a variable speed governor Liquid fuel flows from the supply tank by gravity through the fuel strainer and sediment bulb to the carburetor Air enters these naturally aspirated systems through the air cleaner where dirt and abrasive material are removed Clean air and fuel is metered to the engine by the carburetor in varying pro portions to m et the changing demands of O load and speed The variable speed gov Si ernor controls the carburetor throttle to admit a greater or lesser volume of air fuel mixture This supports the operator s demand for engine speed and provides power to maintain that speed up to the capacity of the engine The operation inspection repair and adjustment of the various parts of the fuel system are covered in the following divisions of this service manual section under appropriate major headings CARBURETORS 5 4 NN NA ATC X AX y UIT i CLINCH END OF SCREWS AFTER ASSY TILE a n 9 su Azz ue A D IS SSS dira
18. anifold aut matic heat control Other conditions influencing power loss l Loss of engine compression due to piston blow by or valve leakage 2 Valve timing error 3 Excessive intake valve stem and guide clearance 4 Loss of valve lift due to cam wear or valve lever adjustment 5 Ignition timing error 6 Detonation or surface ignition due to a Hot spots in the combustion chambers exposed sharp cor ners or burned spark plugs b High altitude piston equipment used in altitudes below that for which they were designed E SG O x d c Use of fuel having too low an octane rating 7 Misfiring due to poor condition of ignition system or loss of engine com pression 8 Unsatisfactory operating tempera ture due to condition of cooling system 9 Plugged exhaust system muffler or spark arrester 10 High pressure PERRE of hydraulic power supply 11 Slippage of drive wheels or drive belt 12 High friction losses in transmission of power proper adjustment of implement and re sulting excessive draft requirement AIR CLEANERS Oil bath type air cleaners protect the engines from entry of dust and abrasives only so long as they are properly main tained The Operator s and Preventive Maintenance Manuals instruct the operator to remove clean and refill the oil cup every day or after every ten hours of operation more frequently when operating under dusty con
19. ating tempera ture due to water pump or thermostat failure etc 5 Spark plug burning or fouling 6 Ignition timing error 7 Misfiring due to poor condition of ignition system 8 Use of high viscosity engine oil 9 High friction loss in transmission or final drive due to lack of or improper lubrication i 10 Brakes dragging ll Excessive drive wheel slippage due to worn lugs or lack of sufficient wheel weights 12 Improper adjustment of implement resulting in excessive draft requirement 13 Excessive drive belt slippage in belt driven applications Fuel system conditions affecting power loss l Low fuel float level 2 Obstructed fuel passages jets or screens from dirt or fuel gum 3 Obstructed air bleeds in carburetor 4 Lean setting of idle and main adjust ments 16 5 Air leakage between carburetor and manifold or between manifold and intake valve ports or cracked intake manifold A d Note Conditions where engine would draw in unfiltered air will also result in rapid and excessive engine wear from dust and abrasives 6 Carbon or coke in intake manifold at hot spot or heated jacket restricting A the amount of air fuel mixture available to the engine 7 Excessive clearance between throttle shaft and throttle body 8 Poor governor action due to wear misalignment or binding of moving parts 9 Plugged air intake and or air cleaner 10 Failure of m
20. be adjusted to its individual engine 1 Synchronizing the governor to carburetor throttle movement Because of possible change in center to center distance between governor and carburetor due to removal and replace ment of manifold carburetor or governor assemblies the linkage between the gov ernor and carburetor must be adjusted to establish the throttle position in relation to governor weight position This adjust Set e ment insures the full power response of a c Lengthen control rod one turn d wide open throttie when the governor from the above condition to GO _Sweights are collapsed by reduction in rpm compensate for wear and 3 by application of heavy load This gov E reconmect gt ernor to carburetor linkage must be free x from binding throughout its range of d After tightening the control rod i movement Adjustment procedure for all clevis lock nut check to be sure engines follows that both ends of the control rod are in the same plane to elim a With engine stopped advance the inate possibility of binding on d operator s engine speed control levers lever to about half speed posi tion sufficient to create tension e Move operator s engine speed on the governor spring control lever a few times be l tween half speed and low speed b Disconnect governor to carbu position checking the governor retor control rod either end to carburetor control
21. clevis to place spring load on throttle lever insert cotter pin and tighten lock gt nut on clevis Return the speed control hand lever to a position slightly advanced from low idle position In this condition check the governor to carburetor control rod for any tendency toward binding It may be necessary to loosen the clevis lock nut and reposition the clevis slightly to in sure both ends being in the same plane to eliminate binding after which the lock nut is retightened Refer to the division on governor for coverage of governor adjustments Assemble the choke control wire and tube being sure full movement of choke valve is assured with the full movement of choke control knob Inspection and Repair Before disassembly of the carburetor clean the outside surfaces of dirt accumu lations so that the solvent used to clean the dismantled parts will not become contam inated In order that individual parts may be given a thorough inspection cleaning is important The use of a good carburetor cleaning solvent is necessary to dissolve gum and varnish like coatings commonly found in carburetors The slow buildup of these coatings in jets and calibrated openings of the carburetor restricts the normal flow of fuel and must be complete ly dissolved and removed to restore the original fuel flow characteristics Where a good commercial carburetor cleaner is C not available equal rts of alcohol and be
22. ditions The frequency bedi oe cup _ di A 53528 Ilust 13 Exploded view of typical air cleaner Farmall and International series of this cleaning under dusty operating con ditions to be governed by the dirt build up found in the cleaner oil cup Again quot ing the Operator s and Preventive Main tenance Manuals Never allow dirt to build up in the cup more than one half inch After every fifty to sixty hours of operation the entire air cleaner should be deep 13 Indicated power loss due to im i I removed disassembled and thorou hl washed di Air sel Intake cover gt pipe Clamps i Lower f ae screens A 53529 lust 14 Exploded view of typical air cleaner utility series Collector pre cleaners are available Illust 17 shows air entering the air in as special attachments for use in very take pipe through the regular cap where dusty operating conditions to assist in the heavy screen prevents entry of large extending the period of use between nec particles of trash The air then passes essary cleaning and servicing The col down to the oil cup where it is drawn lector pre cleaners are used on the type through the oil bath As the air passes of cleaners shown in Illust 13 and replace up through the screens above the oil cup the air intake cap some oil is carried up with the air coat ing the screens Fin
23. drive oil seal in crankcase ing gaskets insure proper ignition timing as follows l With the engine positioned at top dead center of number one cylinder firing stroke locate the single punch mark be tween teeth of idler timing gear Use chalk to mark top surface of two teeth on each side of punch mark 2 Chalk the rear end of the punch marked tooth on the governor drive gear 3 Install the governor assembly meshing the marked gear teeth as shown in Illust 24 i 4 Position the ignition unit distributor rotor arm and A drive shaft lugs for fir ing number one cylinder See Illust 25 Install ignition unit on engine meshing A lugs and B drive slots 5 Advance or retard ignition distribu tor until spark occurs as the Top Dead Illust 24 C 60 engine installing governor assembly seal omitted to better illustrate gear mesh Center mark on fan drive pulley aligns with pointer while hand cranking engine See Illust 26 Distributor rotor arm in No 1 firing position A 22688A Illust 25 Assembling the ignition unit to engine with unit and engine in No 1 firing position 27 Ilust 26 C 60 engine timing pointer and timing marks Install the C 123 and C 135 engine gov ernor assembly and ignition unit using new mounting gaskets insure proper igni tion timing as follows Do l With the engine positioned at top dead center of number one cylinder firing stroke insert
24. e dust and abrasives are removed on contact with the oiled Cover screens As the oil drains back down e from the screens dirt is flushed back down to settle to the bottom of the oil cup Sleeve A 38035_ Crankcase breather connection IlIust 15 Collector type pre cleaner disassembled for cleaning Pre screener attachments are available GO for use where a considerable amount of lt lt Clean air leaves or coarse dirt is encountered to assist in extending the period of use be en Oil cu see Dusty air tween necessary cleaning of air intake uni ST sa Partially clean air cap These attachments replace the reg assembly sad E es ular air intake cap on the type of cleaners Oil level Air bubbles il di shown in Ilust 13 Oil cup assembly E Oil drops A 32102A Illust 17 Cross section of a typical air cleaner showing movement of air and oil in the unit The efficiency of the air cleaner is at its best when oil and screens are clean this efficiency drops rapidly as the oil and screens become loaded with foreign material A 47408 Proper and efficient functioning of the 7 ir Illust 16 Disassembled 5 two piece and 6 one piece a Cleaner is an important factor GKE types of pre screener attachments to provide curing maximum power and maximum a greater intake screen area engine life A most careful inspection 18 of the air cleaner and its connections should be
25. earing should be replaced when after thorough cleaning it is found rough A 53077B Governor to carburetor control rod 4 Governor speed change rod 5 Bracket 6 Maximum speed stop adjust ment 7 Governor spring retainer 8 Governor spring 9 Lever and rockshaft assembly 10 Oil seal rockshaft 11 12 Bushings 13 Plug expansion 14 15 Housing and gasket 16 Rockshaft fork Illust 22 Exploded view of C 221 and C 263 engine governor 26 Installation and Adjustment Install the C 60 engine governor ig nition drive oil seal with seal lip facing forward the seal must be square in the crankcase bore and positioned 23 32 inch in from the ignition mounting flange face See Ilust 23 The seal mating surface on the outside diameter of the gear hub must be smooth and free of cuts or scratches to prevent rapid wear or dam age to seal lip Any sharp edges on gear hub slots should be removed to prevent damage to seal during installation of gov ernor assembly Install the C 60 engine governor as sembly and ignition unit using new mount 17 Set screw 18 Thrust ball bearing 19 Sleeve retainer ring 20 Governor weights 21 i Thrust sleeve 22 Carrier retainer ring 23 Carrier 24 Bearing retainer ring 25 Governor shaft ball bearing 26 Bearing retainer 27 28 Governor shaft and key 29 Drive gear 30 Complete rotating assembly Illust 23 C 60 engine locating governor ignition
26. eed stop screw or adjustment to secure specified fast idle speed See reference and illus tration numbers Item 13 Iliust 20 Item 9 Illust 21 and Item 6 Ilust 22 Be sure that governor speed change linkage is being held against the stop screw in its new position when the tach ometer reading is taken Note Adjustment of the maximum speed stop to allow increased tension to be placed on the governor spring by the op erator s engine speed control lever will result in increased engine speed Adjust ment to reduce tension which can be placed on the governor spring will result in re duced engine speed WIDE OPEN THROTTLE GOVERNOR TO CARBURETOR CONTROL ROD GOV CONTROL ROD GOV CONTROL ROD TURN BUCKLE IlIust 30 Cross section of C 221 and C 263 engine governor MAXIMUM SPEED STOP ADJUSTMENT 31 3 Low idle speed adjustment Smooth low speed engine operation de depends upon careful adjustment of car buretor idle air fuel mixture at the speci fied engine low idle speed Good governor performance also is dependent on this smooth engine operation and free throttle shaft movement near closed throttle posi tions Any tendency of the carburetor throttle to stick or bind in its low idle closed position will cause the governor to surge excessively C 221 and C 263 engine carburetors have throttle shaft positioned off center to overcom tendency of manifold vacuum to hold throttle plate
27. ellerank Adjust the ball joint until the bellerank s in the position 9 32 inch shown Govemor control balancing spring Govemor control lower rod Governor 13 16 inch d Illust 31 Adjustments to correct engine speed control lever position Farmall 460 and 560 series International 460 utili ty series tractors To insure an effective range of opera tor s engine speed control lever move ment on the 460 and 560 Series Tractors the following linkage adjustments are nec essary These basic settings are made with governor rockshaft lever in position 33 to hold the carburetor throttle closed They will result in a full range of govern or movement in response to the hand le ver movement where linkage is not worn excessively Farmall 460 and 560 Series Tractors To correctly position the operator s engine speed control lever proceed as follows a Set the governor at low idle by moving governor rockshaft le ver to vertical position to hold carburetor throttle closed against its stop screw This governor position must be held until adjustments are complet ed b Disconnect the governor control balancing spring and the gov ernor control rod and adjust turnbuckle Illust 30 until the governor control rod operating lever is in the position 13 16 shown in Ilust 30 c Disconnect the governor control upper rod and adjust the ball joint on the governor control
28. for Illust 12 1 Gasket carburetor 2 Elbow and strainer assembly 3 Valve idle adjusting needle 4 Spring retainer idle adjustment 5 Body assembly throttle 7 Seal throttle shaft 8 Retainer seal 9 Shaft assembly throttle 11 Screw throttle stop 12 Gasket fuel Valve 13 Needle valve assembly 14 Axle float 15 Tube idle filler 16 Bowl assembly fuel 18 Plug 19 Gasket plug 20 Jet main metering 21 Gasket main jet 22 Plug drain 22A Cock drain 23 Filler drip plug 24 Plug choke shaft hole 25 Screw choke plate 26 Plate choke 27 Seal choke shaft 28 Retainer seal 29 Bracket assembly 31 Shaft choke 32 Gasket discharge nozzle 33 Nozzle discharge 34 Air Bleed well vent 35 Float assembly 36 Gasket bowl 37 Screw throttle plate 38 Plate throttle valve 39 Venturi 40 Jet idling 41 Plug throttle shaft hole 4 Poor setting of idle or main adjust ments to match fuel or to meet a continu ing load condition 5 Failure to return choke valve to full open position 6 Plugged air intake and or air cleaner 7 Failure of manifold automatic heat control Other factors that can influence fuel economy 1 Loss of engine compression due to piston and ring condition or valve leakage 2 Improper valve timing 3 Loss of valve lift due to cam wear or valve lever adjustment i 4 Unsatisfactory oper
29. fying part num b r to be found stamped on a metal disc riveted to the throttle body when selecting replacement parts Make sure you are using the parts catalog for the tractor and engine involved and that parts selected are from list headed with the carburetor iden tifying parts number Failure to take this precaution when renewing parts could re sult in a carburetor completely out of calibration and an operation lacking power or economy Illust 10 Service tool No HC 80 for installing and re moving main adjusting scraw seats 460 560 and 660 tractors 13 Assembly and Adjustment Upon reassembly of the carburetor be sure all new gaskets and seals are used throughout and are properly installed to insure gas tight connections Use care when assembling fuel bowl to throttle body to prevent dama ge to the float assembly or the idle jet tube When replacing the idle adjusting screw and the main jet adjusting screw turn them down carefully until lightly seated Then back them up to approximately one turn open for the idle screw and five turns open for the main screw Forcible seating of these screws will result in damage to the tapered face of the screw and to its seat The throttle stop screw should be set to hold the throttle plate slightly open These settings of the idle screw and the throttle stop screw serve only as a starting point for idle adjustment Adjustment of the carburetor should not be attemp
30. governor pinion with com plete rotating assembly into the crankcase meshing the marked tooth on the cam gear with the marks between teeth of the gov ernor pinion l 2 Install the governor housing assem bly being sure first that the governor spring is properly assembled See Illust 29 See also that the governor shaft spring and thrust pin is in place in the front end of the shaft _3 Position the ignition unit distributor i rotor arm and A drive shaft lugs for fir dI ing number one cylinder Install ignition unit on engine meshing A lugs and B drive slots Illust 25 i i b pp 4 Advance or retard the ignition dis tributor until spark occurs as Top Dead Center mark on fan drive pulley aligns B with pointer while hand cranking the en gine See Illust 27 28 Top dead center Illust 27 C 123 and C 135 engine timing pointer and timing marks Install the C 221 and C 263 engine gov ernor assembly using new mounting gas kets The governor drive gear may be meshed in any position in these engines since ignition unit is not involved in the governor drive After installation of either new or over hauled governor assemblies in the engines covered in this manual section it is im portant that a thorough check of all four adjustments be made The basic governor assembly may be in perfect condition but in order to insure its full range of control it must
31. losing the throttle and thereby decreasing the engine speed until the decreasing centrifugal force and the reduced spring tension again balance each other 22 When a change in load occurs there is a momentary change in engine speed This causes the governor weights to move in ward or outward thereby opening or clos ing the throttle sufficiently to maintain a reasonably constant engine speed up to the full load capacity of the engine The speed variation between fast idle and rated load speed will normally be about 10 percent in these tractor governors Adjustment is provided in the linkage between the governor and the carburetor to synchronize the position of the throttle with a position of the governor weights This adjustment is most important since it insures the full power response of a wide open throttle when the governor weights are collapsed by the reduction in speed due to application of a full load to the engine In review With an engine supporting its load and maintaining a desired gov erned speed three factors have reached an almost perfect balance These are the forces of 1 governor spring tension 2 centrifugal force on governor weights counteracting the effects of 3 load on the engine speed Slight changes in load within engine capacity will cause slight changes in engine speed upsetting the bal ance of forces and thereby opening or closing the carburetor throttle until the forces are again brough
32. maintain a selected engine speed within reasonably constant limits under varying load conditions by proportioning the fuel to the load For its action the governor depends upon centrifugal force developed by weights rotating about a shaft A variable governor spring is used to counteract the centrifugal force or outward movement of the weights This movement of the gover nor weights through suitable linkage con trols the carburetor throttle opening When the operator starts the engine and sets the engine speed control lever for a desired speed the governor weights move outward with the increasing speed until the centrifugal force on the weights counterbalances the tension of the gover nor spring When this condition is reached the carburetor throttle has also been moved to a position where the air fuel mixture admitted is sufficient to maintain this desired speed The operator controls engine speed by use of the engine speed control lever in creasing or decreasing the governor spring tension not by direct connection with the carburetor throttle valve Increasing the governor spring tension moves the governor weights inward which in turn moves the throttle further open thereby increasing the engine speed until the increased centrifugal force of the gov ernor weights counterbalances the greater spring tension Decreasing the governor spring tension allows the centrifugal force to move the weights outward c
33. nzol may be used E i After the dismantled parts have remained in the solvent long enough to dissolve the coatings remove and rinse in petroleum base cleaning solution Dry all parts with compressed air blowing through all jets and channels in both directions to assure that they are clear and clean Caution Do not use drilis or wires to clean calibrated openings any slight enlargement of these jet openings will affect the operation Use only gum solvent and compressed air for cleaning Throttle Body and Fuel Bowl The castings should be inspected for damage or broken flanges Check mating surfaces for warpage Where such warp age does not exceed 0 910 inch the sur face involved may be lapped on a flat surface using 00 sandpaper Clean thoroughly after the sanding operation Normal clearance between the choke shaft and bowl casting bore is 0 002 to 0 005 inch Where use of a new shaft will still result in a shaft clearance of 0 007 inch or more the bowl casting should be replaced Excessive wear at this point makes it impossible to seal out dirt at the seals The normal clearance between the throttle shaft and throttle body bore is 0 001 to 0 003 inch Where the use of a new throttle shaft will not hold the clear _ ance below 0 005 inch the throttle body assembly should be replaced Excessive wear of this throttle shaft bore will result in dirt and air leakage past seals and poor alignment of the throttle plate
34. op dead center of number one cylinder compression stroke Some reassembly time may be saved if Note the engine is turned to this position before removal of the governor assembly Moisture and sludge accurnula tions in the engine indicate that the engine has been running over long periods of time below normal operating temperature Thermostat operation should be checked on those tractors so equipped and the tractor operator informed on his need to maintain operating temperature Before removing any of the governor assemblies for inspection or repair clean the surrounding area and the various con necting points to prevent entry of dirt into those parts which remain with the engine After disassembly of the governor start The decision on what new parts should the cleaning of parts with a clean container be used to rebuild ths governof assembly E of clean solvent Wash ball bearings first ill be based upon the wear found Sade Do not spin bearings while washing Turn condition of the followi ts them slowly back and forth while dipping EEE Sek the bearing up and down in the solvent to 1 dislodge dirt Blow out with compressed i air holding the parts to prevent the air blast from spinning them to avoid pos Weights pins and weight carrier Clearance in excess of 0 003 inch over that specified between pins and weights or carrier sible scratching of balls and grooves Flush again in clean solvent and blow dry 2 Go
35. op screw Where such extreme setting of bumper spring is found necessary it would indicate excessive fric tion or sticking is occurring in rn aate Earra aea de TR PT closing of throttle C 60 C 123 and C 135 engines only Adjust carburetor throttle stop screw to secure the specified low idle speed and set idle fuel mixture screw for smoothest engine operation Advance operators speed change lever for a few seconds and a gain idle the engine rechecking adjustments for specified low idle speed and smoothest oper ation Place operators speed change lever in maximum speed posi tion Notice the fast idle speed on service tachometer With thumb and finger pull carburet or throttle lever toward open position sufficient to gain 50 rpm fast idle speed Release throttle lever instantly the gov ernor will react by closing the throttle and opening again seek ing its balance Under this con dition two or three surges of the governor are considered normal Excessive surging would indicate binding in car buretor throttle assembly or governor rockshaft and link age assembly as outlined pre throttle assembly or governor rockshaft assembly This should be corrected and the bumper spring readjusted 4 Operator s engine speed control lever linkage In the preceeding adjustments covering fast idle and low idle speeds it was noted D that some readjustment of the operator s speed control lever linkage may
36. pe ie a E i nn and 660 560 460 inder 340 1132 r ice Manual B o 1 uf A A N ba E gt O Ma Tractor Serv ile in F Tractor Series Cub EEE de Sa GZ CONTENTS Specifications General Description Carburetors ee e e e e e e e zr ez e re zr zer ee ee ree Principal Parts ezer ezz e der e Carburetor Operation 7 4 7 Removal and Installation of Carburetor e e Inspection and Repair FIORE CERA e ez ee e er e zz e rz e Assembly and Adjustment SEE ESE ESE E ear Diagnosing Engine Troubles lt lt lt E Sere Sse acer ETZE EE e Air Cleaners Manifold and Exhaust System Engine Governor Specifications Ss Saf Aes E d See Se EU d ee E e E ae Principles of Operation Removal Inspection and Repair Installation and Adjustment 10 13 14 17 19 21 21 22 23 26 Make Yourself More Indispensable SELL SERVICE Servicemen can often sell related items or equipment by showing the customer how the items will be of value to him When you check a customer s equipment regarding the service he asks for you can frequently show him how a few extra service dollars
37. rod in all Hold carb retor throttle against positions for interference or its stop in wide open position binding i and adjust length of governor to carburetor control rod so that it may be reconnected free 2 Adjusting governed fast idle speed ly without moving throttle lever l or governor lever To protect the engine from excessive To speed change Maximum speed Maximum speed _ Speed change lever hand lever a adjusting adjusting _ A stop screw stop screw a Governor spring dd ae housing KI To carburetor L_ throttle eer Throttle rod adjustment and yoke 7 N Rockshaft j i Shaft end i fork I e Yoke pin a Governor and clearance Governor Thrust sleeve Weight pin Rockshaft Rockshaft bracket magneto drive weights and bearing fork si gear 18T i f A 55194 O Illust 28 Cross section of C 60 engine governor assembly Cra i 29 an ptt deetara GEO IT speed and also to provide sufficient speed operating temperature Air to maintain the engine s rated load the cleaner oil and engine lubricant i governed fast idle speed adjustment must viscosity should be correct for I be properly made Be sure the service ta the season of use and both bed chometer used is accurate Do not expect should be near operating tem the tractor tachometer to be sufficiently perature accurate for this operation Adjustment procedure for all engines
38. s which remain with the engine Fail ure to perform this simple operation may result in an ultimate condition much worse than that which made the carburetor re moval necessary After the carburetor is removed in spect the air cleaner pipe and hose for possible air leaks wherein dirt and abra sives could enter the engine Discard the carburetor flange gasket Clean manifold flange of any scraps of old gasket which may adhere and would prevent sealing of new gasket When reinstalling the carburetor care must be used in securing air and dust tight connections of air cleaner pipe and hose Renew if necessary Before reconnecting the fuel line to the carburetor remove and clean sediment bowl and screen Use new bowl gasket in replacing sediment bowl Open the fuel tank valve momentarily to flush line and observe for free flow of fuel A 14754B Ilust 5 Fuel strainer showing bowl removed for clean ing 10 After the carburetor is reinstalled on the manifold recheck the adjustment of the governor to carburetor control rod to in sure wide open throttle at full load demand of governor as follows With engine stop ped advance engine speed control hand e ver to create tension on the governor spring Adjust length of governor to car buretor control rod so that the rod slides freely into the throttle lever when the throttle is wide open Lengthen governor to carburetor control rod by one turn in its
39. ssembly throttle 7 Gasket fuel bowl 8 Gasket needle valve cage 9 Needle valve assembly 10 Idle jet ll Axle float 12 Nozzle discharge 13 Retainer choke shaft seal 14 Seal choke shaft 15 Spring choke lever 17 Filler and plug drip hole 18 Plate choke valve 19 Retainer throttle shaft seal 20 Seal throttle shaft 21 Strainer screen 22 Valve idle adjusting needle 23 Spring retainer idle adjustment 24 Float assembly 25 Gasket discharge nozzle 26 Bowl assembly 27 Gasket main jet 28 Jet main metering 29 Shaft choke valve 30 Air bleed main Diagnosing Engine Troubles Servicemen should not be too quick in condemning carburetor operation Poor fuel economy loss of power poor recovery from overload or poor acceleration are not necessarily results of inadequate car buretion Fuel system conditions that can affect fuel economy while important are relatively few in number Make sure that none of the following conditions exist but don t limit your investigation to the fuel system 40 6 eiza 7 lb err Sg ber A 49497A Illust 12 Exploded view of Zenith 68X7 carburetor 140 240 and 340 series tractors Fuel system conditions affecting fuel economy l Float valve leakage or high fuel level 2 Damaged or enlarged jet openings 3 Unbalanced conditions due to bowl gasket failure or dirt plugged air bleeds i or vents Legend
40. st 20 Exploded view of C 60 engine governor 1 2 3 Governor to carburetor control rod 4 5 Rockshaft extension and bracket 6 Key 1 Governor spring 8 Rockshaft and spring lever 9 Rockshaft oil seal 10 Rockshaft bearing 11 Governor speed change lever 12 Lever shaft 13 Maximum speed stop screw 14 Housing cap screw 15 Housing expansion plug Examine hook ends of governor springs and mating holes in spring levers for _ wear Replace these parts where appreci Cys able wear is found Le Care must be taken in the reassembly 16 17 18 19 20 21 22 23 24 25 26 27 28 29 D 8 11 12 13 14 15 I I y I i i I y B 8259 Governor shaft front bushing Bumper spring and adjustment Dowel pin Housing and gasket Sleeve retainer ring Thrust ball bearing Thrust sleeve Governor rear bushing Governor weights and pins Governor shaft carrier and base Rockshaft fork b 6 wn of the governor rockshaft rockshaft fork bearings and seal to insure Uniformly b smooth movement of the rockshaft from one extreme of movement to the other Lubricate the rockshaft oil seal thoroughly upon installation Some slight friction resulting from drag of the oil seal on the shaft is unavoidable but friction from any A Wy A Z oY SI NN other source must be held to a minimum Any rough jerking movement of the rock shaft must also be eliminated to prevent
41. surging and erratic governor action Governor shaft end clearance is adjust ed in the C 60 engine governor by placing 0 020 inch thickness of feeler gauge stock LY Z YG A A 49502 1 2 3 Governor to carburetor control rod 19 Seal retainer 4 Governor speed change lever 20 Rockshaft fork 5 Governor spring 21 Rockshaft 6 Oil seal 22 Drive gear carrier and shaft 7 Washer 23 Governor weights 8 Governor spring lever 24 Thrust sleeve i 9 Maximum speed stop screw 25 Thrust ball bearing 10 Housing cap screw 26 Governor shaft spring ll Housing 27 28 32 Bumper spring and adjustment 12 13 14 Oil filler cap 29 Weight pins 15 Rockshaft needle bearings 30 31 Governor shaft thrust and 16 Plug expansion stop pins 17 Rockshaft bushing 33 Rockshaft retainer pin 18 Rockshaft seal 34 Gasket 25 Cig between drive gear and governor base when pressing the gear on the assembly After gear is pressed in place the end clearance should be within the range of 0 020 to 0 025 inch See Illust 28 End clearance in the C 123 and C 135 engine governor shaft is eliminated by the 26 governor shaft spring and thrust pins used in its design See Illusts 21 and 29 In the C 221 and C 263 engine governor the internal fit of the 25 governor shaft ball bearing controls its end clearance See Illusts 22 and 30 A new ST 552 ball bearing will have end clearance in the range of 0 004 to 0 0065 inch This b
42. t Synchronizing the Governor under heading Governor Installation and Adjustment Exhaust mufflers in vertical and under slung mountings are used on tractors cov ered by this section Some applications of these tractors may call for the use ofa spark arrester attachment as insurance against fire hazards from exhaust sparks These items require no servicing but should be examined from time to time for dama ge which would restrict the exhaust of the engine Such restriction would cause loss of power and reduce engine valve life IE Specifications Tractor Series Engine Series Governor Spring Use rockshaft lever hole Spring number Outside diameter Wire size Number of coils Bumper spring Governor weight to pin clearance Engine rpm Low idle 25 Fast idle 25 Rated Load 10 251 464 R1 46 944 DA 369 686 R2 369 686 R2 367 739 RI 6250 7700 7700 8125 0915 0915 0915 0915 8 1 2 6 6 15 001 004 001 004 475 425 2016 1575 1800 1400 001 004 425 2200 2000 001 004 001 010 425 2200 2000 367 739 R1 8125 0915 001 010 425 1980 1800 GE 372 709 Rl 8125 1055 14 1 2 001 010 425 2640 2400 YWONUIA09 INIONI Principles of Operation The engine governors used with the carbureted engines covered in this section are all of the fly ball variable speed type They are designed to
43. t distortion of throttle shaft or plate Float Assembly loaded with fuel or if the float lever axle bearing is worn excessively Inspect top side of the float lever for wear where it contacts the fuel needle valve Replace the float assembly if float is i t The float axle should be replaced if any wear can be detected on its bearing surfaces Throttle body Venturi Fuel valve seat Float axle support Float i PS Float axle i A 31935 illust 6 Float assembly and fuel needle valve removed from carburetor 13 iz 15 f Needle valve cage to 7 Sf iy d Ee AZZ A n e ka gt ZZZ Main metering jet Set stop to control float A 23164A drop Illust 7 Float measurements and liquid level IH 3 4 carburetor Cub series C 60 engine 12 Fuel Needle Valve and Seat If any wear can be detected on the valve face the needle valve and seat assembly should be replaced The float assembly its axle and the fuel valve are responsible for maintaining a stable and correct fuel level all parts must be maintained in good condition Only slight bending of the float lever should be necessary to secure the correct float height The float lever stop where used should be adjusted to control float drop Proper setting of float drop prevents the float from striking and wear ing on the bottom of the bowl when opera ting over rough terrain _ FLOAT HEIGHT FUEL
44. t into balance To insure smooth surgeless and prompt response of the governor all of its moving parts and linkage must move freely to follow slight changes in engine load speed Should binding occur at any place before sufficient centrifugal force _ or spring tension is built up to overcome the friction and move the throttle valve Friction increases and binding often occurs because of wear and misalignment of the carburetor throttle shaft Sludge deposits in the governor housings can cause sluggish or rough action of governor ing parts and examine each for damage or parts and linkage Wear of governor excessive wear No attempt should be B weights pins sleeve rockshafts or rock made to salvage old gaskets or seals b shaft lever also result in surging and er They should be carefully removed from ratic governor action l i the assembly and replaced with new to insure an oil tight dust proof operation Removal Inspection and Repair Where sludge accumulations are found in the governor housing corrosion of bearing surfaces may have occurred These rough bearing surfaces and their increased frictional drag are responsible for poor governor action Excessive bearing clearance also results from sludge corrosion f In the four cylinder engine governors the governor drive gear also serves as the ignition unit drive These governor drive gears are marked for proper mesh with mating gears at t
45. ted until the engine has reached normal operating temperature Then ad just throttle stop screw for the specified low idle speed and set the idle adjusting screw for smoothest engine operation Advance the engine speed control lever for a few seconds and again idle the engine rechecking the idle adjustments for speci fied low idle speed and smoothest operation Where gasoline carburetor is equipped with a main fuel adjustment screw its only function is to limit the fuel going to the engine for greater economy when unit is to be used for extended periods under light loads Where heavy work is to be performed in which the full power of the engine is required this main fuel adjust ing screw must be set five turns off its seat The main metering jet which forms the fuel adjustment screw seat has been calibrated to provide a full power mix ture and must not be restricted by use of the adjusting screw when the full power of the engine is required The main fuel adjusting screw packing nut should be tightened sufficiently to prevent leakage and to hold screw firmly in position Location of the carburetor number 7 eE 7 ei arr TT A I Ma D N 10 _ 6 N IPB 3011 C lust 11 Exploded view of IH 3 4 carburetor Cub se ries tractors 14 Legend for Ilust 11 i Gasket carburetor 2 Shaft throttle valve 3 Spring retainer idle set screw 4 Plate throttle valve 6 Body a
46. the cranking period As the engine fires and engine speed increases a spring loaded valve in the choke plate opens to let in more air and lean out the rich mixture As the engine gathers speed and warms up the choke valve is manually opened to further lean out the air fuel ratio to a normal mixture An opening is provided in the bottom of the carburetor main air intake to drain off any excess unvaporized fuel which may return from the manifold This opening is protected against the entry of dust and abrasives by a felt filler See 16 Ilust 1 Air cleaner pipe rro Illust 2 Removing the carburetor Farmall Cub and In ternational Cub Lo Boy tractors Should this filler shrink and deteriorate from age dirt may be drawn into the en gine contributing to excessive engine wear Should this opening be painted over or otherwise plugged no drainage is possible and flooding with raw fuel can occur if the fuel float valve leaks Governor connecting rod d edi a Air cleaner connection je Illust 3 Removing the carburetor Farmall and Interna tional 140 240 and 340 series tractors l BEZ wire A 53527 is Illust 4 Removing the Carburetor 460 560 and 660 se ries tractors Removal and Installation of Carburetor Before removing the carburetor from the engine for cleaning inspection or repair clean the area and various connect ing points to prevent entry of dirt intothose part
47. truction of automatic heat control valve 20 of heat from the effective surfaces and also restrict the amount of air fuel mix ture available to the engine through the reduction of the internal diameter of the manifold Either condition will result in loss of power and unsatisfactory operation Correction is by removal of the deposits Extremely heavy deposits may result in uneven expansion and cracking of the mani fold casting requiring replacement of the part Manifold gaskets must be in good con dition to prevent entrance of dirt and abrasives into the engine and to maintain the air fuel ratio of the intake mixture To prevent overstressing of studs and to insure even compression of the gaskets the stud nuts should be tightened to speci fications with a torque indicating wrench On the four cylinder engines the manifold to engine stud nuts should be tightened to 20 25 ft lbs On six cylinder engines covered in this section the manifold to engine stud nuts should be tightened to 20 30 ft lbs The four bolts attaching the in take and exhaust halves of the six cylinder manifold should be tightened to 25 30 ft Ibs After removal and replacement of intake and exhaust manifold assembly for any reason it is advisable to re check the carburetor throttle position in relation to governor position This is necessary due to possible change in center to center distance between governor and carburetor see number 1 adjustmen
48. ver to full speed position and bring dynamometer load up slowly Check carburetor throt tle position with each slight in crease in load Read the service tachometer at the in stant the loading causes the throttle to reach its wide open position throttle le ver against stop This rpm should be within the range of Rated Load Speed as given in specifications Note Failure to meet the range of rated load speed would indicate wrong governor spring in the assembly weak governor spring wear of spring hook ends or worn holes in spring levers lost mo tion due to wear or loose assemblies in correct assembly of governor spring in rockshaft lever C 123 and C 135 en gines or sluggish governor action due to excessive friction in moving parts d Low idle speed may be checked after power take off is desen gaged to remove all load of P T O drive and dynamometer from engine SERVICE BULLETIN RECORD Important Information in this manual section is subject to change or supplementing from time to time as a result of field experience and engineering modifications As Service Bulletins are received record them on this page for handy reference whenever this manual is to be used Print entries in ink Bulletin Date Book i No Issued No Topic or part of machine involved _ IT a e _ cs 36 GSS 1132 5 15 59 Lithographed in U S A
49. vernor shaft bearings and thrust a second time Examine under good light bearing Rough pitted bearing surfaces to determine if further cleaning is neces of either plain or ball type bearings sary Adda few drops of oil to the balls and grooves then and only then spin by 3 Rockshaft rockshaft fork bearings hand to test for roughness and wear and levers Worn or damaged rockshaft f rockshaft fork or spring levers Rough Wash and clean the remainder of the pitted bearings and bearing surfaces rotating parts in solvent examining the weights carrier and weight pins for Where all three conditions are found damage or wear Clearance between new the use of new complete governor assem E weights and new pins for each governor bly should be considered since the few are shown on specification page Clear parts which can be salvaged may not cover ances found to exceed those specified by the labor cost of overhaul 0 003 inch or more would be considered excessive and parts should be renewed Where conditions l and 2 are involved the rotating assembly including new bear Wash and clean the housing and remain ings weights and pins should be used 23 fuer rei prgn alli pre cati ATL BUS Le NSA ZA Where only the governor weight and pin clearance is found questionable only these individual parts need be replaced In all cases new gaskets and new seals must be used to prevent entry of dirt and lost of oil Illu
Download Pdf Manuals
Related Search