Stiga RS100 Instruction manual

WORKSHOP MANUAL
WORKSHOP MANUAL
The manufacturer reserves the right to make all the necessary technical or commercial improvements to
its products, so there may be some differences between the series of engines and the contents of this
manual. However the basic specifications and different operating procedures will remain the same.
by STIGA - No use of the illustrations or 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 manufacturer is not liable for damages
or injuries arising from operations performed by individuals or inadequate facilities.
PRODUCTION YEAR
Rel. 0.0 2018
RS100 - RSC100
RS100 - RSC100

Release 00 - 03/2018
Engine RS100 - RSC100
page 3Service manual
INTRODUCTION..................................................................................................... 5
1. RULES AND PROCEDURES FOR SERVICE CENTRES .......................................... 6
1.1. Guarantee validity .................................................................................................................................6
1.2. Service repairs after guarantee period................................................................................................6
1.3. Faultnotication.....................................................................................................................................6
1.4. Spare parts request................................................................................................................................6
2. GENERAL AND SAFETY REGULATIONS............................................................. 7
2.1. Qualicationofoperators .....................................................................................................................7
2.2. Safety measures.....................................................................................................................................7
2.3. Precautions during servicing.................................................................................................................7
2.4. Warning labels........................................................................................................................................8
2.5. Necessary equipment ...........................................................................................................................8
2.6. Symbols and terms used for safety purposes......................................................................................8
3. TECHNICAL DATA AND SPECIFICATIONS........................................................ 9
3.1. Identication...........................................................................................................................................9
3.2. Technical data .......................................................................................................................................9
3.3. Adjustments ............................................................................................................................................9
3.4. Expendable materials............................................................................................................................9
3.5. Limiti di utilizzo ........................................................................................................................................9
3.6. Tightening torques................................................................................................................................10
3.7. Table of Tightening torques .................................................................................................................11
3.8. Identication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 SYSTEM........................................................................................... 18
6.1. Removing the starter assembly ..........................................................................................................18
6.2. Replacing the rope ..............................................................................................................................18
6.3. Replacing the hooks............................................................................................................................19
7. INTAKE SYSTEM ............................................................................................... 20
7.1. Maintenanceandreplacementofthelterelement.......................................................................20
7.1a. Maintenanceofspongelteringelement (model RS100).........................................................22
8. CARBURATION ( valid for RSC100 model) ................................................................ 23
8.1. Removing and cleaning the carburettor ...........................................................................................23
8.2. Replacing the carburettor...................................................................................................................26
CONTENTS
<< BACK >>

page 4Release 00 - 03/2018
Engine RS100 - RSC100
Service manual
8.3. Adjusting minimum speed ..................................................................................................................26
8.4. Adjusting maximum speed.................................................................................................................26
8.5. Adjusting the carburation....................................................................................................................26
9. CARBURATION ( valid for RS100 model)................................................................... 27
9.1. Removing and cleaning the carburettor ...........................................................................................27
9.2. Replacing the carburettor...................................................................................................................30
9.3. Adjusting maximum speed.................................................................................................................30
9.4. Adjusting the carburation....................................................................................................................30
10. GOVERNOR SYSTEM OF THE CARBURETTOR ............................................... 31
10.1. Adjusting of accelerator cable ( model RSC100)..........................................................31
10.2. Adjusting maximum speed ( model RSC100)..............................................................................32
10.2a. Adjusting maximum speed
( model RS100).........................................................................................34
10.3. Replacing the lever support ( model RSC100).............................................................................35
10.3a. Replacing the lever support ( model RS100) .............................................................................36
11. IGNITION....................................................................................................... 37
11.1.Checkingtheefciencyoftheignitionsystem ................................................................................37
11.2. Adjusting the air gap and checking the coil ....................................................................................38
11.3. Replacing the coil................................................................................................................................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mufer .................................................................................................43
14. ENGINE BLOCK - External operations ........................................................ 44
14.1. Checking the heating unit seal ..........................................................................................................44
14.2. Adjusting the valve clearance ...........................................................................................................45
14.3. Dismantling and replacing the complete fan...................................................................................46
14.4. Blow-by check .....................................................................................................................................47
14.5. Replacing the upper compression ring of the engine shaft (fan side)...........................................47
14.6. Replacing the lower compression ring of the engine shaft (sump side)........................................48
15. ENGINE BLOCK - Overhauling internal parts............................................. 49
15.1. Removing the engine ..........................................................................................................................49
15.2. Carter opening .....................................................................................................................................50
15.3. Dismantling and checking the camshaft and counterweight governor........................................51
15.4. Dismantling and checking the piston, piston rings, connecting rod and engine shaft ................53
15.5 Overhauling the valves .......................................................................................................................59
16. TROUBLESHOOTING...................................................................................... 62
CONTENTS
<< BACK >>

Release 00 - 03/2018
Engine RS100 - RSC100
page 5Service manual
The purpose of this manual is to provide to Service
Centres the information necessary for a correct
maintenance, dismantling and repair procedure
for engines RS100 and RSC100.
Interventions on the engine must be performed in
accordance with instructions in the following pages
and with safety regulations in force in the country in
which the engine is operated, and only by authori-
sed and appropriately trained personnel.
In every manual page the following informations
are described:
page 16 Release 00 - 03/2018
Engine RS100 - RSC100
Service manual
5.1. Emptying and removing the tank
1 - Remove the ring (1) of the petrol pipe (2) from
the tank side and drain all the fuel from the tank
and the pipe into a suitable container.
2 - Remove the starter assembly (3) by loosening
the three nuts (4).
3 - Loosen the rear screw (5) and remove the tank
(6).
ove operations in
reverse.
WARNING: Before 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).
7) and blow compressed
air through it so as to remove any deposits inside.
4 - Keeping the hole (8) in the spigot closed, pour
about 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 used in the manual, highlighting
particularly important information, risks, warnings
and prescriptions:
Warns of operations that should be carried
out with utmost care to avoid impairing the
functionality and safety of the lawnmower.
Warns of operations that should be carried
out with utmost care to avoid injury to the
operator.
 NOTE:Referstospecicadvicebythema-
nufacturer.
Reference to another procedure or part of
the manual.
Recommends that washers and O-rings are
checked and replaced if necessary.
Refers to use of special tools.
Shows all the operations requiring different
intervention methods depending on the en-
gine version.
NOTE: During the description of procedures,
the indications “right”, “left”, “front”, “rear”,
“upper” and “lower” refer to the engine
mounted on the lawn tractor seen from the
user’s perspective.
Please read all the contents of this manual to be-
come familiar with the basics of the engine, which
is fundamental for operating in a logical manner
without making errors or wasting time.
INTRODUCTION
A
B
C C
EF D
INDEX
<< BACK >>

page 6Release 00 - 03/2018
Engine RS100 - RSC100
Service manual
1.1. Guarantee validity
The warranty is supplied under the terms, procedu-
res and limits stated in the contract.
1.2. Service repairs after guarantee period
The Service Centre must write a report for each
intervention containing the serial number of the
engine [ 3.1], and summary information about
the problems complained of, the intervention made
and possible spare parts used..
A copy of these reports must be kept and made
available to the manufacturer together with the
replaced parts, in case clients should make further
complaints.
1.3. Faultnotication
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 best trou-
bleshooting procedure.
1.4. Spare parts request
When asking for spare parts, you must quote
their code by referring to the exploded views
corresponding to the year of manufacture reported
on the nameplate [ 3.1].
1. RULES AND PROCEDURES FOR SERVICE CENTRES
<< BACK >>
INDEX

Release 00 - 03/2018
Engine RS100 - RSC100
page 7Service manual
2. GENERAL AND SAFETY REGULATIONS
IMPORTANT: Before commencing with any
intervention, carefully read the information
provided in the present manual, in particular
the following safety regulations.
2.1. Qualicationofoperators
All maintenance, disassembly and repairs must be
carried out by expert mechanics who are familiar
with all the accident prevention and safety regu-
lations after reading through the procedures in this
manual.
2.2. Safety measures
All the engines are built in conformity with the Eu-
ropean safety regulations in force.
To maintain initial safety levels in the long term, the
Service Centre should take proactive measures by
making checks whenever possible.
Every time you are asked to service the engine (or
the lawnmower on which it is installed), you should:
• check:
- that the safety devices function correctly;
- that the casings and protection covers have not
been removed;
- thatthenameplatesorspecicationlabelshave
not been removed or made illegible, (as they
form an integral part of the safety devices).
• also:
- restore to proper working order any safety devi-
ces which have been manipulated or removed;
- replace ineffective, damaged or missing guards
and covers;
- replace illegible labels;
- donotcarryoutoperationsormodications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 points automatically voids the war-
ranty and the responsibility of the manufacturer.
2.3. Precautions during servicing
As well as following the usual accident prevention
regulations that apply to most repair shops, we
recommend you:
- disconnect the spark plug cap before servicing;
- protect hands with suitable working gloves,
especially when working near the cutting unit;
- check that you do not cause accidental petrol
leaks or other losses;
- do not smoke when working on the tank or when
handling petrol;
- do not inhale oil or petrol fumes;
- clean up all traces of spilt petrol immediately;
- do not pollute the environment with oil, petrol or
other waste and dispose of all waste in accor-
dance with the laws in force.
Exhaust gas contains carbon monoxide,
which is highly toxic, odourless and co-
lourless. Avoid inhaling.
- Perform tests on the engine in a well-ventilated
environment or in the presence of adequate
exhaust gas extraction systems.
<< BACK >>
INDEX

page 8Release 00 - 03/2018
Engine RS100 - RSC100
Service manual
2. GENERAL AND SAFETY REGULATIONS
2.4. Warning labels
On the canopy motor, in a immediately identica-
tion position, are some indication or prescription
plates for the safety operator.
The plates are as follows:
•• ••• ••••
RS100 XXX
1 - Fire hazard due to:
- Petrol or oil
Prevent by following the precautions below:
- Do not smoke or ignite a ame in the vicinity of
the petrol or oil;
- Turn engine off before adding petrol;
- Do not spill petrol on overheated or electric parts
of the engine;
- Handle or store petrol or oil in well-ventilated
areas;
- Use non-flammable oil for cleaning engine
parts.
-Accumulationofammablematerial
Prevent by following the precautions below:
- Remove dry leaves, chips, pieces of paper, dust or
other ammable material which has accumulated
in or is attached to the engine.
- Electrical cabling
Short circuits can cause res. Prevent by following
the precautions below:
- Always keep the electrical connections of the
machine clean and tightly sealed;
- Tighten any loose 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 being used, open doors and windows to ensu-
readequate ventilation and, therefore, avoid gas
poisoning.
4 - Motor label (see [ 3.1])
2.5. Necessary equipment
All the operations can be carried out with the tools
normally used in a good garage.
The , symbol used for certain interventions
indicates that special tools or equipment are re-
commended.
2.6. Symbols and terms used for safety purposes
Some paragraphs in this manual are preceded by
symbols which indicate the following:
Operations that should be carried out with ut-
most care to avoid impairing the functionality
and safety of the engine and/or lawnmower
on which it is installed.
Operations that should be carried out with
utmost care to avoid injury to operators.
“WARNING” stresses the risk of injury to oneself
and others if instructions and regulations are not
observed.
1 2 3
4
<< BACK >>
INDEX

Release 00 - 03/2018
Engine RS100 - RSC100
page 9Service manual
Daily progressive
number
3.1. Identication
Every motor is marked with a serial number on the
base and applied on the canopy; this serial number
characters and can identify:
•• ••• ••••
RS100 XXX
The serial number must be reported on every opera-
ting sheet in the warranty application and is funda-
mental for identifying and ordering spare parts.
3. TECHNICAL DATA AND SPECIFICATIONS
3.4. Expendable materials
RSC100 RS100
Petrol Unleaded (green)
minimum 90N.O.
Engine oil - da 5 a 35 °C
- da -15 a + 35°C
SAE 30
10W30
Spark plug
GGP K7 RTC
Starter rope ø 3x2350 mm
3.5. Limiti di utilizzo
The following table gives the use limits of certain
components subject to wear, after which the com-
ponent must be replaced.
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 12,05 mm
Maximum
connecting
rod diameter
gudgeon pin
side 12,05 mm
crank side 24,07 mm
3.2. Technical data
RSC100 RS100
Displacement 100 cc
Bore 58 mm
Stroke 37,8 mm
Compression ratio 8,5 : 1
Minimum speed
(SLOW) ( r.p.m. ) 1800 (±100) -
Maximum speed
(FAST) (r.p.m.) 2900 (±100) 2800 (±100)
Fuel tank capacity 0,85 litres
Oil sump capacity 0,40 litres
Dry weight 7,80 kg
3.3. Adjustments
Distance between spark plug
electrodes 0,6 - 0,8 mm
Coil air gap 0,35 - 0,45 mm
Inlet valve clearance 0,15 - 0,20 mm
Exhaust valve clearance 0,15 - 0,20 mm
Year of
manufacture
Date
<< BACK >>
INDEX

page 10 Release 00 - 03/2018
Engine RS100 - RSC100
Service 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

Release 00 - 03/2018
Engine RS100 - RSC100
page 11 Service manual
3. TECHNICAL DATA AND SPECIFICATIONS
3.7. Table of Tightening torques
Chapter Ref. Description of screw Tightening torques
5Assembly xing nut 8 - 10 Nm
5Tank xing screw 8 - 10 Nm
6 Fixing nuts, starter assembly 8 - 10 Nm
6 Starter screw 4 - 6 Nm
8 - 9 Fixing nuts carburettor and lter 6 - 8 Nm
10 Support screw, governor assembly 8 - 12 Nm
11 - 14 Spark plug tightening torque 16 - 20 Nm
11 Fixing screw reel 8 - 12 Nm
11 Coil xing stud 8 - 12 Nm
12 Brake support screws 8 - 12 Nm
13 Mufer xing nuts 8 - 10 Nm
13 Mufer xing screw 8 - 10 Nm
14 Screws valve cover 7 - 9 Nm
14 Fan xing 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 xing screw 8 - 12 Nm
15 Fixing screws lower connecting rod cap 11 - 13 Nm
P.S. For the coupling tourque of all standard screws refer to the single table.
<< BACK >>
INDEX

page 12 Release 00 - 03/2018
Engine RS100 - RSC100
Service manual
3.8. Identicationofengineunits
For ease of reference, this manual has subdivided maintenance operations into different sections, each of
which refers 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
<< BACK >>
INDEX

Release 00 - 03/2018
Engine RS100 - RSC100
page 13 Service manual
4. ENGINE TUNING AND TESTING
4.1. Operating guidelines
The engine requires a series of interventions (shown in the table below) in order to ensure minimum basic
maintenance.
Operation First 5 hours Every 5 hours
or daily
Every 25
hours or
every season
Every 50
hours or
every season
Every 100
hours
Check oil level -■---
Change oil *(1) ■- - ■-
Clean mufer and engine -■---
Check air cleaner *(2) -■---
Replace air cleaner *(2) - - ■- -
Check spark plug -■---
Replace spark plug ---■-
*(1) Replace the oil every 25 hours if the engine is working at full load or at high temperatures.
*(2) Clean the air lter more often if the machine is working in dusty areas.
For the operations that are not difcult for the nal
user the assistance centre must maintain the mo-
tor in perfect efciency, in accordance with two
intervention lines:
- Tuning the engine whenever possible.
- Recommending the client 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 efciency.
Tuning should involve:
- external blowing and cleaning the cylinder
head, cylinder and mufer by removing any
remains of grass and mud;
- checking the oil level, topping up or replacing
parts if necessary;
-inspecting the condition of the starter rope and
checking that it functions correctly [ 6.2];
- cleaning and oiling the air lter [ 7.1] e [
7.1a];
- emptying and cleaning the fuel tank and che-
cking the breather pipe [ 5.2];
- adjusting minimum [ 8.3] and maximum
speeds [ 10.2] ( RSC100)
- adjusting maximum speeds [ 10.2a] (
RS100);
- inspecting the condition of the spark plug;
checking the distance between the electrodes
[ 11.1];
- tightening the screws [ 15.2];
- functional test [ 4.3].
Should the checks and adjustments fail to achieve
a satisfactory result, refer to chapter [ 16] for
troubleshooting.
<< BACK >>
INDEX

page 14 Release 00 - 03/2018
Engine RS100 - RSC100
Service manual
4.3. Functional test
A functional test needs to be carried out at the
end of each servicing operation, to check that the
operations made are effective. The test must be
performed in compliance with the safety regula-
tions regarding the use of the lawnmower on which
the engine is installed.
The functional test is carried out as follows:
a. Refuelling and checking the supply system
When you have refuelled the tank with 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 specications [ 3.2].
d. Hot start test
With the engine hot and the throttle control set to
“SLOW” ( RSC100), start the engine a few times
to check it runs normally.
If all of these operations have a positive result, the
engine can be considered fully serviceable and be
returned to the client.
4. ENGINE TUNING AND TESTING
<< BACK >>
INDEX

Release 00 - 03/2018
Engine RS100 - RSC100
page 15 Service manual
5. TANK AND SUPPLY
IMPORTANT: Carefully read the information below before commencing any intervention.
General Information
The fuel supply system comprises the petrol tank connected to the carburettor by a pipe; a mesh lter at
the bottom of the tank prevents deposits and impurities from reaching the carburettor.
The tank is equipped with a lter, located at the bottom of the tank, which prevents deposits and impurities
from reaching the carburettor.
The supply to the carburettor oat 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;
- work in a ventilated environmentawayfromnakedamesorunprotectedsourcesofheat;
- collect any remaining petrol by positioning a suitable container under the engine, avoiding soiling the
work bench;
- remove all traces of spilt petrol immediately;
- check you have connected the pipes before pouring petrol back into the tank.
<< BACK >>
INDEX

page 16 Release 00 - 03/2018
Engine RS100 - RSC100
Service manual
5.1. Emptying and removing the tank
1 - Remove the ring (1) of the petrol pipe (2) from
the tank side and drain all the fuel from the tank
and the pipe into a suitable container.
2 - Remove the starter assembly (3) by loosening
the three nuts (4).
3 - Loosen the rear screw (5) and remove the tank
(6).
4 - When tting, perform the above operations in
reverse.
WARNING:Beforerelling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 lter tube (7) and blow compressed
air through it so as to remove any deposits inside.
4 - Keeping the hole (8) in the spigot closed, pour
about 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
<< BACK >>
INDEX

Release 00 - 03/2018
Engine RS100 - RSC100
page 17 Service manual
5. TANK AND SUPPLY
5 - Empty the tank and dispose of the petrol used
for cleaning in accordance with the laws in force.
6 - Ret the tank [ 5.1] tightening the screws
(5) to the torques indicated.
7 - Replace the starter assembly by securing the
nuts (4) at the specied torque.
WARNING: Beforerelling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
ssures;
- 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
gasket or sponge is damaged.
Tightening torques
4Assembly xing nut 8-10 Nm
5Tank xing screw 8-10 Nm
9
9
10
11
12
<< BACK >>
INDEX

page 18 Release 00 - 03/2018
Engine RS100 - RSC100
Service manual
General information
The starter assembly inside the cover consists of a rope wound around a pulley. The movement from the
pulley to the fan (and therefore to the engine shaft) is transmitted through a pair of couplings. The return of
the pulley and the rewinding of the rope are obtained from a spiral spring.
See the relevant section [ 16] for advice on resolving problems due to the malfunctioning of 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 - Ret 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 gradually release
the return spring.
If the rope breaks, the spring will be already relea-
sed and you will only have to unwind the rope.
3 - Undo or cut the knot at the end of the rope
(5) and remove the section still attached to the
pulley.
1
3
3
3
4
4
5
5
<< BACK >>
INDEX

Release 00 - 03/2018
Engine RS100 - RSC100
page 19 Service manual
6. STARTING SYSTEM
4 - Rotate the pulley (4) through about 6 complete
turns anticlockwise in order to load the spring and
hold it still.
5 - Insert one end of the rope (5) (ø 3mm - length
2350mm) through the guide in the ventilation grille,
into the hole in the pulley (4), and fasten it by tying
a knot.
6 - Insert the other end of the rope into the grip
(6), fasten it with a knot and carefully release the
pulley to allow the rope to rewind itself completely
onto the pulley.
7 - Check that the pulley rotates freely.
8 - After pulling the entire length of the rope, check
that the pulley (4) is able to complete another 2-3
turns before compressing the spring.
9 - Ret 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 the complete set
consisting of hooks, return springs, cover and
screw, as a unit.
4 - When tting, tighten the screw (7) to the torque
indicated.
5 - Ret the starter assembly [ 6.1].
NOTE: Check that the spring lever (10) is
outside the coupling (9).
Tightening torques
3
Fixing nuts, starter assembly 8-10 Nm
7Starter screw 4-6 Nm
Technical information
Starter rope dimensions ø 3x2350 mm
5
6
4
7
8
9
9
10
10
4
<< BACK >>
INDEX

page 20 Release 00 - 03/2018
Engine RS100 - RSC100
Service manual
General information
The intake system uses an air lter directly connected to the carburettor by means of a manifold which
conveys the air/petrol mixture to the inlet valve.
See the relevant section [ 16] for advice on resolving problems due to the malfunctioning of the air
intake system.
Aninefcientltercanletdustordebrisenterthecylinder,causingprematureweartothepistonringsand
cylinder.
The air lter is found on the left hand side of the engine and can be inspected without having to remove
other parts.
The lter assembly is to be removed only to accede the carburettor.
7. INTAKE SYSTEM
7.1. Maintenance and replacement of the lter
element
WARNING: Never run the engine without air
lter.Theenginewouldcertainlybedama-
ged.
1 - Clean the area around the lter cover (1) by
blowing it with compressed air.
2 - Remove the cover (1) by pressing on the upper
tab (2).
WARNING: Close the intake duct to prevent
theentryofforeignobjects(seegure).
3 - Remove the lter element (3).
4 - Check carefully that the element has no holes
or tears, and replace it, if damaged.
22
11
3
3
<< BACK >>
INDEX