Stiga RS100, Workshop Manual

Page 1: ...duplication reproduction or translation even partial of the texts in this document may be made without explicit authorization IMPORTANT NOTICE The information contained herein is intended for Service Operations and professionals only able to competently perform the operations described herein using the appropriate equipment in order to safeguard se curity and performance of the machine The manufac...

Page 2: ......

Page 3: ...Expendable materials 9 3 5 Limiti di utilizzo 9 3 6 Tightening torques 10 3 7 Table of Tightening torques 11 3 8 Identification of engine units 12 4 ENGINE TUNING AND TESTING 13 4 1 Operating guidelines 13 4 2 Engine tuning program 13 4 3 Functional test 14 5 TANK AND SUPPLY 15 5 1 Emptying and removing the tank 16 5 2 Cleaning the tank 16 5 3 Checking and cleaning the breather pipe 17 6 STARTING ...

Page 4: ...oil 39 12 TURNING OFF AND STOPPING THE ENGINE 40 12 1 Checking the control cable 40 12 2 Checking the system for turning off the engine 40 12 3 Checking the brake 41 12 4 Replacing the system for turning off and stopping the engine 42 13 EXHAUST SYSTEM 43 13 1 Removing and replacing the muffler 43 14 ENGINE BLOCK External operations 44 14 1 Checking the heating unit seal 44 14 2 Adjusting the valv...

Page 5: ...out 100 cc of clean petrol into the tank and shake it vigorously to clean the inside 5 TANK AND SUPPLY 6 5 7 8 1 2 3 4 4 A Motor typ for which the page is valid B Reference to the chapter and the argument with the relative numbering C Presence of previous or following chapters from the present chapter D Issue date or possible audit E Audit number F Page progressive numbering Certain symbols are us...

Page 6: ...pt and made available to the manufacturer together with the replaced parts in case clients should make further complaints 1 3 Fault notification The manufacturer should be informed of all faults that recur frequently this allows it to carefully exa mine the problem and make corrections on the production line Similarly the manufacturer shall report any faults traced on its engines indicating the be...

Page 7: ...ces which have been manipulated or removed replace ineffective damaged or missing guards and covers replace illegible labels do not carry out operations or modifications on the lawnmower or on the engine that could af fect their performance or lead to an improper or different use from the one for which it has been designed and approved warn the customer that the failure to comply with the above po...

Page 8: ...connectors or cabling clamps Replace those that are damaged 2 Observe the instructions and warnings contained in the present manual and on the safety plates on the engine Inappropriate functioning and maintenance can result in serious injury or even death 3 Ventilation of closed areas In the event that it is necessary to start the engine in a closed environment or if petrol or cleaning oil is bein...

Page 9: ... RSC100 RS100 Minimum inlet valve stem diameter 5 45 mm Minimum exhaust valve stem diameter 5 42 mm Minimum inlet valve head rim thicknesse 0 6 mm Minimum exhaust valve head rim thickness 1 0 mm Minimum valve spring length 29 4 mm Maximum gap between ends of cylinder rings 0 8 mm Max axial gap for compression rings 0 12 mm Minimum gudgeon pin diameter 11 95 mm Max gudgeon pin piston seat diameter ...

Page 10: ...ice manual 3 TECHNICAL DATA AND SPECIFICATIONS 3 6 Tightening torques 8 10 Nm 8 10 Nm 8 12 Nm 16 20 Nm 6 8 Nm 60 70 Nm 8 12 Nm 7 9 Nm 11 13 Nm 8 12 Nm 8 10 Nm 7 9 Nm 8 10 Nm 8 10 Nm 8 10 Nm 6 8 Nm 8 10 Nm 8 12 Nm 4 6 Nm Mod RSC 100 Mod RS 100 BACK INDEX ...

Page 11: ...rt screw governor assembly 8 12 Nm 11 14 Spark plug tightening torque 16 20 Nm 11 Fixing screw reel 8 12 Nm 11 Coil fixing stud 8 12 Nm 12 Brake support screws 8 12 Nm 13 Muffler fixing nuts 8 10 Nm 13 Muffler fixing screw 8 10 Nm 14 Screws valve cover 7 9 Nm 14 Fan fixing nut 60 70 Nm 14 Blow by closure plate screw 7 9 Nm 15 Union screws under carter and sump 8 12 Nm 15 Counterweight governor fix...

Page 12: ...fers to an engine component unit as indicated in the diagrams below 3 TECHNICAL DATA AND SPECIFICATIONS Carburettor Carburettor Ignition Ignition Carburation control Carburation control Engine block Engine block Air intake Air intake Turning off and Stopping Turning off and Stopping Exhaust system Exhaust system Starting system Starting system Tank and Supply Tank and Supply Mod RSC 100 Mod RS 100...

Page 13: ...a routine maintenan ce program at set intervals e g at the end of the season or before a long period of inactivity 4 2 Engine tuning program As part of general engine tuning or any intervention on the lawn tractor it is recommended that the Ser vice Centre performs a series of operations aimed at maintaining the engine s efficiency Tuning should involve external blowing and cleaning the cylinder h...

Page 14: ... new petrol check the seal of the tank the cap and the car burettor pipe b Cold starting test RSC100 With the throttle control in CHOKE start the engine a few times to check it runs normally c Check the engine rpm When the engine is hot enough check the engine speed with the throttle control set to SLOW and FAST RSC100 the readings should be equal to the specifications 3 2 d Hot start test With th...

Page 15: ...arburettor float chamber is caused by gravity and the volume of petrol taken from the tank as the engine runs is compensated by a breather pipe in the cap See the relevant section 16 for advice on resolving problems due to the malfunctioning of the petrol supply system WARNING All interventions on the supply system must be performed in safe conditions therefore do not smoke always empty the tank w...

Page 16: ...4 When fitting perform the above operations in reverse WARNING Before refilling the tank with new fuel check that the petrol pipe is intact 5 2 Cleaning the tank 1 Remove the tank 5 1 2 Remove the clamp 1 from the side of the tank and disconnect the petrol pipe 2 3 Slide out the filter tube 7 and blow compressed air through it so as to remove any deposits inside 4 Keeping the hole 8 in the spigot ...

Page 17: ...ue WARNING Before refilling the tank with new fuel check that the petrol pipe is intact 5 3 Checking and cleaning the breather pipe 1 Remove the cap 9 and pull out the gasket 10 and the sponge 11 2 Check that the gasket 10 is intact and without cracks or fissures the air passages 12 inside the cap are not clog ged the sponge 11 is not crushed or broken NOTE Always replace the entire cap if the gas...

Page 18: ... the star ting system 6 STARTING SYSTEM 2 6 1 Removing the starter assembly 1 To get access to the starter assembly 1 the cover 2 must be removed by unscrewing the three nuts 3 2 Refit the starter assembly 1 by tightening the cover nuts 3 to the torque indicated 6 2 Replacing the rope 1 Remove the starter assembly 6 1 2 Keep hold of the pulley 4 and slowly unwind clockwise the entire rope 5 to gra...

Page 19: ... check that the pulley 4 is able to complete another 2 3 turns before compressing the spring 9 Refit the starter assembly 6 1 6 3 Replacing the hooks 1 Remove the starter assembly 6 1 2 Loosen the screw 7 and remove the cover 8 putting the spring to one side Be careful not to slip the pulley 4 off its seat 3 Remove the couplings 9 and take out the springs 10 from their seats NOTE Always replace th...

Page 20: ...ilter is found on the left hand side of the engine and can be inspected without having to remove other parts The filter assembly is to be removed only to accede the carburettor 7 INTAKE SYSTEM 7 1 Maintenance and replacement of the filter element WARNING Never run the engine without air filter The engine would certainly be dama ged 1 Clean the area around the filter cover 1 by blowing it with comp...

Page 21: ...ards from the inside Replace the element if it is too dirty 6 Sponge filter element Perform the mainte nance referred to in the paragraph 7 1a 7 Refit the element 3 and the cover 1 into their housings into its housing paying attention to hook up the clips correctly 2 8 model RS100 During the installation of the sponge filter element make sure it is properly posi tioned between the tabs as shown in...

Page 22: ...replace it if damaged WARNING The filter element must be kept clean and oil soaked and must be replaced if bro ken cut or if it is crumbling Do not use compressed air to clean the filter ele ment 3 Wash the filter element with water and detergent and dry with a clean cloth 4 Pour two spoons of clean motor oil onto the element and wring the sponge repeatedly until the oil is evenly spread 5 Remove ...

Page 23: ... tank if petrol is not strictly necessary for the operation to be carried out work in a ventilated environment away from naked flames or unprotected sources of heat collect petrol in a suitable container with a cap using a funnel and avoid spilling it on the work bench remove all traces of spilt petrol immediately check you have connected the pipes before pouring petrol back into the tank 8 1 Remo...

Page 24: ... com pensation spring upwards 6 Disconnect the wire 9 from the choke butterfly lever completely remove the carburettor 10 for the relative compensation spring upwards 11 NOTE Empty any remaining petrol from the tank by removing the drain screw 12 as shown in the figure When finished replace the screw 7 Unscrew the central screw 13 securing the tank 14 and remove the corresponding OR 15 7 8 11 10 B...

Page 25: ...rough the carburettor holes 12 Mount the carburettor following the previous points 8 7 and 6 in reverse order remembering that It is always advisable to replace the washer 18 and the O Ring 15 of the float chamber the float 17 must oscillate freely on the pin 16 the jet 19 should never be modified or replaced with others even if they seem to have the same specifications the choke 22 must open and ...

Page 26: ...um speed must be between 1800 100 rpm 3 Turn the screw 24 until you achieve a stable minimum speed within the above values 8 4 Adjusting maximum speed NOTE This operation is carried out by adju sting the governor system 10 2 8 5 Adjusting the carburation NOTE The carburation is set in the factory and does not normally need changing In the event of irregular functioning clean the car burettor as in...

Page 27: ...if petrol is not strictly necessary for the operation to be carried out work in a ventilated environment away from naked flames or unprotected sources of heat collect petrol in a suitable container with a cap using a funnel and avoid spilling it on the work bench remove all traces of spilt petrol immediately check you have connected the pipes before pouring petrol back into the tank 9 1 Removing a...

Page 28: ...e small rod 7 for the relative com pensation spring upwards 7 Completely remove the carburettor 8 and the gasket 9 NOTE Empty any remaining petrol from the tank by removing the drain screw 10 as shown in the figure When finished replace the screw 8 Unscrew the central screw 11 securing the tank 12 and remove the corresponding OR 13 6 9 7 8 10 11 12 13 BACK INDEX ...

Page 29: ...ed air blowing well through the carburettor holes 13 Mount the carburettor following the previous points 9 8 and 7 in reverse order remembering that It is always advisable to replace the washer 16 and the O Ring 13 of the float chamber the float 15 must oscillate freely on the pin 14 the jet 17 should never be modified or replaced with others even if they seem to have the same specifications the s...

Page 30: ...maximum speed NOTE This operation is carried out by adju sting the governor system 10 2a 9 4 Adjusting the carburation NOTE The carburation is set in the factory and does not normally need changing In the event of irregular functioning clean the car burettor as indicated in section 9 1 Tightening torques 1 Carburettor nuts filter 6 8 Nm 9 CARBURATION valid for RS100 model BACK INDEX ...

Page 31: ... would keep it open the balance between the spring loading and the thrust of the counterweights on the control lever modifies the butterfly opening and adapts the flow of fuel to the engine so that the revolution speed is kept constant with engine load changes See the relevant section 16 for advice on resolving problems related to the governor system 10 1 Adjusting of accelerator cable model RSC10...

Page 32: ...nd then to the FAST position to eliminate any slack Check the RPM again using the engine speed indicator Make sure the accelerator is in the FAST position and check the air lever rod is not already activated or in contact NOTE The engine s maximum speed must be between 2900 100 rpm if you do not read this value proceed as follows 6 Check that the spring 8 is intact and that it is properly position...

Page 33: ...weight device must be checked stop the engine and move the accelerator control to FAST slacken off the control lever 13 locknut 12 without changing the lever 12 position determi ned by the spring 10 and tie engine shaft 9 use a screwdriver to turn pin 14 clockwise to the end of its stroke and then lock the nut 13 10 GOVERNOR SYSTEM OF THE CARBURETTOR 12 13 14 9 8 10 11 BACK INDEX ...

Page 34: ...lows 3 Check that the spring 7 is intact and that it is properly positioned in its seat that the wire 8 and the relative spring 9 are intact and not deformed 4 If the above checks do not show any faults the phasing of the governor s control lever 10 with respect to the counterweight device must be checked stop the engine and make sure that the lever 10 is in the end run position slacken off the co...

Page 35: ...he two screws 15 securing the support 16 to the engine and the clip 17 securing the petrol pipe 5 Turn the lever support and remove the tie rod 18 on the starter throttle lever CHOKE 6 Perform the above operations in reverse order when assembling 7 Replace the filter holder 8 1 and the filter element 7 1 8 Adjust the maximum speed 10 2 Tightening torques 15 Support screw governor assembly 8 12 Nm ...

Page 36: ... 2 Disconnect the spring 7 3 Remove the two screws 13 and replace the lever support 4 Perform the above operations in reverse order when assembling 7 Replace the filter holder 9 1 and the filter element 7 1 8 Adjust the maximum speed 10 2a Tightening torques 13 Support screw governor assembly 8 12 Nm Technical information Maximum speed 2800 100 g 1 Special equipment 5 Speed indicator 7 13 13 BACK ...

Page 37: ...park test 2 Connect the tester 3 to the spark plug cap 4 and to earth on the engine 5 Activate the starter and see in the instrument if the spark jumps 3 If the test has a positive result clean the electro des 2 with compressed air and adjust the distance to 0 6 0 8 mm Remount the spark plug and tighten it to the specified levels Unless otherwise required proceed to verify system components as ind...

Page 38: ...e the coil 7 At the bottom of the machine to which the engine is fitted release the safety brake Rotate the fan 11 so as to bring the magnetic inserts next to the poles of the core of the coil 5 Insert a 0 35 mm thickness gauge 12 between the complete fan 11 and the coil poles 7 push the coil until the poles come in contact with the thickness gauge and secure screw 9 and stud 10 with the flywheel ...

Page 39: ...isconnect the faston of the earth cable 6 3 Undo the screw 9 and the stud 10 and remove the coil 7 4 Mount the new coil and regulate the air gap according to the procedure indicated in points 4 and 5 in section 11 2 5 Connect the faston of the earth cable 6 6 Refit the starter assembly 6 1 Tightening torques 1 Spark plug tightening torque 16 20 Nm 9 Coil fixing screw 8 12 Nm 10 Coil fixing stud 8 ...

Page 40: ...ecking the system for turning off the engine 1 Disconnect the coil Faston connector 6 2 Using a multimeter 7 as an ohmmeter make contact with the leads on the points indica ted in the figure The instrument should read microswitch pressed lever pulled 0 microswitch free lever released Otherwise replace the system for turning off and stopping the engine General information The engine is turned off a...

Page 41: ...t the control lever 5 moves freely and remove any remains of grass and mud 4 Refit the starter assembly 6 1 5 Start the engine release the lawnmower lever and check that the engine stops within 3 secon ds 6 If it stops after 3 seconds replace the entire assembly 12 4 because the spring or the friction pad are not capable of ensuring complian ce with braking times WARNING Never return the lawnmower...

Page 42: ...tor 9 5 Loosen the two screws 10 and the spring 11 Remove the support bracket 5 6 When fitting perform the above operations in reverse tightening the screws 10 to the torque indicated 7 Refit the starter assembly 6 1 and the filter assembly 8 1 mod RSC100 or 9 1 mod RS100 8 Start the engine release the lawnmower lever and check that the engine stops within 3 secon ds Tightening torques 10 Brake su...

Page 43: ...he muffler 1 Remove the two nuts 1 and the screw 2 that fix the guard 3 and the muffler 2 Take out the muffler 4 and the heatproof baffle 5 3 On assembly thoroughly clean the cylinder contact surface removing all deposits or fragments on the hea tproof baffle always replace damaged mufflers always replace the heatproof baffle 5 if it is broken or cracked tighten the two nuts 1 and the screw 2 to t...

Page 44: ...tool 3 into the spark plug hole and connect the supply pipe to a compressed air socket with a pressure of approximately 4 bar 58 psi 4 On opening the air tap 4 the manometer gauge on the engine side should position itself in the green zone and remain there for about 30 se conds If the gauge falls rapidly it means that the compression is poor NOTE Lack of compression could be due to incorrect valve...

Page 45: ...uge 8 to check the gap betwe en the rocker arm and the tip of the valve stem the gauge should pass between without forcing and without a further gap 5 Slack is adjusted by loosening the dowel 9 and suitably adjusting the register nut 10 to obtain the following values Inlet IN 0 15 0 20 mm Exhaust EX 0 15 0 20 mm 6 Following adjustment check that the pushrods 11 are properly inserted in the rocker ...

Page 46: ...extraction tool remove the complete fan 17 as indicated in the diagram Ensure that the engine shaft key is retained NOTE If it is difficult to disassemble the fan use a hammer and hit the extractor screw 6 When fitting the complete fan check that the key 18 is in good condition and replace it if deformed Close the nut 13 to the indicated couple 7 Refit the coil 14 tightening the screw 15 and the s...

Page 47: ... gasket 22 and refit the closure plate 20 tightening the screw to the torque indicated 5 Refit the complete fan 14 3 14 5 Replacing the upper compression ring of the engine shaft fan side 1 Remove the complete fan 14 3 2 Take out the spline key 18 3 Use a thin screwdriver inserted under the sealing lip to extract the oil seal ring 23 4 The new ring 24 must be inserted with the help of a pipe 25 wi...

Page 48: ...g lip to extract the oil seal ring 29 4 Make a paper tube 30 around the shaft to protect the sealing lip and insert the new ring 31 so that it enters its housing 5 Complete the insertion with the help of a pipe 32 of a diameter of approximately 30 35 mm Tightening torques 2 Spark plug tightening torque 16 20 Nm 6 Valve cover fixing screws 7 9 Nm 13 Fan fixing nut 60 70 Nm 19 Blow by closure plate ...

Page 49: ...p by removing the filler plug and turning the mower on its side 3 Disconnect the engine brake cable 1 and the throttle cable 2 RSC100 4 Remove the blade assembly and undo the three screws 3 which are accessible from the bottom of the lawnmower Grasp the engine at points which offer a secure grip taking account of the overall weight given in the relevant table 3 2 3 3 3 1 2 BACK INDEX ...

Page 50: ...n the two points indicated 6 verify the phasing between the engine shaft and the camshaft If necessary re set the phasing referring to the indications provided 7 On assembly follow the steps described in re verse and clean the contact surfaces removing any remai ning silicone evenly distribute the silicone seal THREE BOND 1207 7 as shown in the figure ensure that the two centring pins 8 are proper...

Page 51: ...ing for wear The value must not be lower than 24 10 mm IN and 24 13 mm EX 6 Check the regular movement of the pressure reducer 10 and the efficiency of the spring 11 the whole group must always be replaced in the case of breakage or irregular operation of the pressure reducer 7 Check that the irregolar centrifugal 12 that are not present ruptures of the lubrication pallets 8 Turn the governor s ge...

Page 52: ...e to position the washer 17 correctly on the opposite side 11 Before fitting the camshaft ensure that the two tappets 18 are correctly housed in their seats 12 When refitting the camshaft maximum care must be taken to match up the two references 19 and 20 punched on the gears so as to ensure correct distribution phasing 13 During assembly refer to the operations in section 15 2 always remembering ...

Page 53: ...te fan 14 3 3 Open the cover 15 2 4 Remove the camshaft 15 3 5 Dismantle the connecting rod 21 cap 22 fixed with two screws 23 take note of any reference marks for refitting 6 Push the connecting rod 22 so as to ensure the piston 24 enters the cylinder 25 fully 7 Pull the engine shaft 26 out completely 8 To remove the piston 24 pull the connecting rod 22 as shown in the figure 9 Use the special ex...

Page 54: ...nd must be replaced The cylinder must be replaced if it shows striping due to a seizure 10 Use a section of an old ring 29 to carefully clean the inside of the piston 24 ring housings en suring that the oil passage holes are not blocked 11 To check the wear in the piston ring housings fit a new ring and measure the residual space with a feeler gauge 30 The piston must be replaced if it is greater ...

Page 55: ...s A on the piston 24 and replace the piston if they are more than 12 05 mm even at a single point 15 Fit the cap 21 to the connecting rod 22 and check the diameter from the gudgeon pin side and the crank side replace the connecting rod if the values are greater than B 12 05 mm on the gudgeon pin side C 24 07 mm on the crank side If the connecting engine shaft is outside measure ment tolerances or ...

Page 56: ...otruding part of the shaft place the engine shaft on two prismatic guides 33 and with the help of a comparator 34 placed at the end check the displacement by rotating the shaft The shaft must be replaced if the displacement exceeds 0 10 mm IMPORTANT A bent shaft must never be re paired WARNING DANGER A bent shaft causes ab normal vibrations and could be dangerous when the machine is used 18 To ref...

Page 57: ...amping rings 31 to the piston 24 NOTE The marking on the piston must be directed towards the intake The connecting rod must be mounted with the marking 38 facing upwards 20 Put the piston into the ring compression tool 39 21 Oil the inside of the piston liberally and insert the piston with the marking facing the exhaust 32 31 24 31 22 38 39 39 BACK INDEX ...

Page 58: ...he greatest care to ensure that the two position references 19 and 20 punched on the engine shaft and camshaft gears coincide ensuring the correct distribution phasing 24 Close the carter and fix the screws 6 to the indicated couple 15 2 25 Whenever the engine shaft is dismantled and refitted it is always necessary to replace the sealing ring on the fan side 14 5 replace the sealing ring on the su...

Page 59: ... 6 1 2 Open the crank case 15 2 and remove the piston 15 4 3 Move the rocker arms 40 press down the spring seal cap 41 and move it sideways to remove from the valve stem 42 IMPORTANT The intake and exhaust valves are of different sizes 4 Use an emery cloth to remove all incrustations from the valve head and check the thickness of the rim A the valve must be replaced if the margin A is less than 0 ...

Page 60: ...7 When mounting carefully clean the valve guides and housings of any foreign body apply a film of oil on the valve stems before inser ting them in their respective housings ensure the proper position of the intake valve and exhaust valve which can be notice by the different sizes Intake larger Exhaust smaller 8 Replace the intake valves and check that the oil seal 44 is in place 43 44 BACK INDEX ...

Page 61: ...13 Nm Technical information Oil sump capacity 0 40 litri Diameter aspiration cam 24 1 mm Diameter discharge cam 24 13 mm Maximum segments gap in the cylinder 0 8 mm Max compression ring axial gap 0 12 mm Minimum gudgeon pin diameter 11 95 mm Max gudgeon pin housing diameter on piston 12 05 mm Max connecting rod diameter gudgeon pin side 12 05 mm crank side 24 07 mm Diam connecting rod s pin on eng...

Page 62: ... val ve Clean the carburettor housing and needle valve 8 1 RSC100 and 9 1 RS100 or repla ce the carburettor 8 2 RSC100 and 9 2 RS100 Choke blocked not closed RSC100 Check and clean the carburettor and the choke 8 1 The spark plug is badly connected or faulty Check spark 11 1 or replace spark plug Blocked air filter Execute the filter cleaning 7 1 and 7 1a only for RS100 Valve malfunction Check the...

Page 63: ...r Replace the carburettor gaskets 8 1 RSC100 and 9 1 RS100 Carburettor dirty Check and clean the carburettor 8 1 RSC100 and 9 1 RS100 Insufficient pressure Check correct valve operation 15 5 Check that the spark plug is secured 11 1 Check for any cracks in the casing Check wear and tear of the piston rings 15 4 The coil air gap has been poorly adjusted Adjust the air gap 11 2 and if the problem pe...

Page 64: ...ab 11 1 The engine does not stop within 3 seconds after it has turned off Faulty or no clutch lining Replace the engine stopping system 12 4 The engine uses a lot of oil Faulty blow by operation Check and or replace the blow by system 14 4 Check the con dition of the air filter 7 1 Poor piston ring seal Replace the rings 15 4 Excessive gap between the guide and the inlet valve stem Check and or re...

Page 65: ...Release 00 03 2018 Engine RS100 RSC100 page 65 Service manual BACK INDEX ...