Aprilia RS 250. Manual - part 23

8

INFORMAZIONI PER LE RIPARAZIONI

SERVICING INFORMATION

INFORMACIONES PARA LAS
REPARACIONES

INFORMACIONES PARA LAS 

REPARACIONES

SERVICING INFORMATION

8

CONTENTS

TROUBLESHOOTING .............. 8-7

ENGINE .................................... 8-7
CARBURETTOR - RADIATOR... 8-9
ELECTRICAL SYSTEM ........... 8-10
BATTERY - BRAKES ............... 8-11
CHASSIS ................................ 8-12

WIRING DIAGRAM  ................ 8-19

ELECTRICAL SYSTEM 
INSPECTION .......................... 8-22

BATTERY RECHARGING 
INSPECTION - REGULATOR - 
GENERATOR - 
SPARK PLUGS ........................ 8-22
CARBURATION - 
EXHAUST VALVES CONTROL 
MOTOR - EXHAUST VALVES 
PHASE CONTROL .................. 8-28
THROTTLE SENSOR - 
ELECTRONIC REV COUNTER -
NEUTRAL SWITCH AND 
LATERAL STAND 
SWITCH INSPECTION  ........... 8-28

CABLE, WIRE, HOSE 
ROUTING PASSAGE AND 
FASTENING ............................ 8-29

COOLING CIRCUIT ................. 8-32
MIXER OIL HOSE ROUTING .. 8-33
CARBURETTORS AIR 
CIRCUIT .................................. 8-34
FUEL HOSE ROUTING  .......... 8-35

SPECIAL TOOLS  .................... 8-37

TIGHTENING TORQUES  ....... 8-41

TECHNICAL 
SPECIFICATIONS ................... 8-50

INDICE

BUSQUEDA DE LAS
AVERIAS ................................. 8-13

MOTOR .................................. 8-13
CARBURADOR - RADIADOR  . 8-15
INSTALACION ELECTRICA .... 8-16
BATERIA - FRENOS ................ 8-17
CHASIS ................................... 8-18

ESQUEMA ELECTRICO .......... 8-19

CONTROL DE LA 
INSTALACION ELECTRICA .... 8-22

CONTROL DE LA RECARGA 
DE LA BATERIA - REGULADOR -
GENERADOR - BUJIAS  ......... 8-22
CABURACION - MOTOR DE 
CONTROL DE LAS VALVULAS 
EN EL ESCAPE - 
CONTROL FASE VALVULAS .. 8-26
SENSOR DEL GAS
CUENTARREVOLUCIONES 
ELECTRONICO - CONTROL DEL
FUNCIONAMIENTO DEL 
INTERRUPTOR DEL PUNTO
MUERTO E INTERRUPTOR 
DEL CABALLETE LATERAL  ... 8-28

RECORRIDO, PASO Y 
FIJACIONES DEL CABLEO - 
CABLES - TUBOS  ................... 8-29

CIRCUITO DE 
REFRIGERACION ................... 8-32
TUBOS DEL CIRCUITO DEL 
ACEITE DEL MEZCLADOR  .... 8-33
CIRCUITO DEL AIRE DE 
LOS CARBURADORES ........... 8-34
TUBOS DEL COMBUSTIBLE  . 8-35

HERRAMIENTAS 
ESPECIALES ........................... 8-37

PARES DE APRIETE ................ 8-43

CARACTERISTICAS 
TECNICAS .............................. 8-55

8 - 7

M

SERVICING INFORMATION

Complaint

Symptom and possible causes

Remedy

Engine will not start,

Compression too low

or is hard to start

1. Excessively worn cylinder or piston rings.

Replace.

2. Stiff piston ring in place.

Repair or replace.

3. Gas leaks from the joint in crankcase, cylinder or

cylinder head.

Repair or replace.

4. Spark plug too loose.

Tighten.

5. Broken, cracked or otherwise failed piston.

Replace.

6. Worn crankshaft oil seal.

Replace.

Plug not sparking
1. Fouled spark plug.

Replace.

2. Wet spark plug.

Clean and dry.

3. Defective ignition coil.

Replace.

4. Open or short in high-tension cord.

Replace.

5. Defective ignition system.

Repair or replace.

No fuel reaching the carburettor
1. Clogged air vent hole in the fuel tank cap.

Clean.

2. Clogged or defective fuel cock.

Clean or replace.

3. Defective carburettor needle valve.

Replace.

4. Clogged fuel pipe.

Clean.

Engine stalls

1. Fouled spark plug.

Clean.

easily

2. Defective ignition system.

Repair or replace.

3. Clogged fuel pipe.

Replace.

4. Clogged jets in carburettor.

Clean.

Noisy engine

Noise appears to come from piston
1. Piston or cylinder worn down.

Replace.

2. Combustion chamber fouled with carbon.

Clean.

3. Piston pin or piston pin bore worn.

Replace.

4. Piston ring groove worn.

Replace.

5. Piston pin bearing worn.

Replace.

Noise seems to come from clutch
1. Worn splines of countershaft or hub.

Replace.

2. Worn teeth of clutch plates.

Replace.

3. Distorted clutch plates, driven and drive.

Replace.

Noise seems to come from crankshaft
1. Rattling bearings due to wear.

Replace.

2. Big-end bearings worn and burnt.

Replace.

3. Crankshaft bearing worn and burnt.

Replace.

Noise seems to come from transmission
1. Gears worn or rubbing.

Replace.

2. Badly worn splines.

Replace.

3. Primary gears worn or rubbing.

Replace.

TROUBLESHOOTING

ENGINE

SERVICING INFORMATION

M

8 - 8

Complaint

Symptom and possible causes

Remedy

Slipping clutch

1. Clutch control out of adjustment or loss of play.

Adjust.

2. Weakened clutch springs.

Replace.

3. Worn or distorted pressure plate.

Replace.

4. Distorted clutch plates, driven and drive.

Replace.

Dragging clutch

1. Clutch control out of adjustment or too much play.

Adjust.

2. Some clutch springs weakened while others are not.

Replace.

3. Distorted pressure plate or clutch plates.

Replace.

Transmission will

1. Broken gearshift cam.

Replace.

not shift

2. Distorted gearshift forks.

Replace.

Transmission will

1. Broken return spring on gearshift fork shaft.

Replace.

not shift back

2. Gearshift fork shafts are rubbing or sticky.

Repair or replace.

Transmission jumps

1. Worn shifting gears on drive shaft or countershaft.

Replace.

ou of gear

2. Distorted or worn gearshift forks.

Replace.

3. Weakened stopper spring on gearshift stopper.

Replace.

Engine idles

1. Spark plug gap too wide.

Adjust.

poorly

2. Defective ignition coil.

Replace.

3. Defective ignition system.

Repair or replace.

4. Float-chamber fuel level out of adjustment in

carburettor.

Adjust.

5. Clogged jets.

Clean.

Engine runs

1. Spark plug gap too narrow.

Adjust.

poorly in

2. Clogged jets.

Clean.

high-speed range

3. Defective ignition coil.

Replace.

4. Defective ignition system.

Repair or replace.

5. Float-chamber fuel level too low.

Adjust.

6. Clogged air cleaner element.

Clean.

7. Clogged fuel pipe, resulting in inadequate fuel

supply to carburettor.

Clean and refuel.

8. Exaust valve control out of adjustment.

Adjust.

9. Defective exhaust valve control unit, actuator or

exhaust valve.

Replace.

Dirty or heavy

1. Oil pump out of adjustment.

Adjust.

exhaust smoke

2. Damaged or worn crankshaft oil seal.

Replace.

Engine lacks

1. Worn piston rings or cylinder.

Replace.

power

2. Spark plug gap incorrect or defective ignition system.

Adjust or replace.

3. Clogged jets in carburettors.

Clean.

4. Float-chamber fuel level out of adjustment.

Adjust.

5. Clogged air cleaner element.

Clean.

6. Imbalance of the carburettors.

Adjust.

7. Sucking air from intake pipe.

Retighten or replace.

8. Supplying too much engine oil.

Adjust oil pump.

Engine overheats

1. Heavy carbon deposit on piston crown.

Clean.

2. Not enough oil supply.

Adjust oil pump.

3. Defective oil pump or clogged oil lines.

Replace or clean.

4. Fuel level too low in float chambers.

Adjust.

5. Sucking air from intake pipes.

Retighten or replace.

6. Using incorrect engine oil.

Use prescribed oil.

7. Defective cooling system.

See radiator section.

8 - 9

M

SERVICING INFORMATION

Complaint

Symptom and possible causes

Remedy

Trouble with starting

1. Starter jet is clogged.

Clean.

2. Starter pipe is clogged.

Clean.

3. Air leaking from a joint between starter body

and carburettor.

Check and retighten.

4. Starter plunger is not operating properly.

Repair.

Idling or low-speed

1. Pilot jet is clogged or loose.

Check and clean.

trouble

2. Air leaking from carburettor's S.I.P.C. hose or starter.

Check.

3. Pilot outlet or by-pass is clogged.

Check and clean.

4. Starter plunger is not fully closed.

Check and adjust.

5. Imbalance of carburetors.

Adjust the carburettors.

Medium- or high-

1. Main jet is clogged.

Check and clean.

speed trouble

2. Jet needle is clogged.

Check and clean.

3. Throttle valve is not operating properly.

Check throttle valve
for operation.

4. Filter is clogged.

Check and clean.

Overflow and fuel

1. Needle valve is worn or damaged.

Replace.

level fluctuations

2. Float is not working properly.

Check and adjust.

3. Foreign matter has adhered to needle valve.

Clean.

4. Fuel level is too high or low.

Adjust float height.

5. Clogged carburettor air vent pipe.

Clean.

6. Spring in needle valve is broken.

Replace.

CARBURETTOR

Complaint

Symptom and possible causes

Remedy

Engine overheats

1. Not enough cooling water.

Add.

2. Radiator core is clogged with dirt or trashes.

Clean.

3. Defective thermostat, stuck in closed position.

Replace.

4. Clogged water passages.

Clean.

5. Air trapped in the cooling circuit.

Bleed out air.

6. Defective water pump.

Replace.

7. Incorrect cooling water used.

Change coolant.

Engine overcools

1. Defective thermostat, stuck in full-open position.

Replace.

2. Extremely cold weather.

Put on the radiator
cover.

RADIATOR

SERVICING INFORMATION

M

8 - 10

Complaint

Symptom and possible causes

Remedy

Spark plugs soon

1. Mixture too rich.

Adjust carburettor.

becomes fouled

2. Idling speed set too high.

Adjust carburettor.

with carbon

3. Incorrect gasoline.

Change the gasoline.

4. Clogged air cleaner element.

Clean.

5. Spark plugs type too cold.

Replace by hot type
plug.

Spark plugs become

1. Worn piston rings.

Replace.

fouled too soon

2. Piston or cylinder worn.

Replace.

Spark plug electrodes

1. Spark plug too hot.

Replace by cold type

overheat or burn

plug.

2. The engine overheats.

Turn up.

3. Spark plug loose.

Retighten.

4. Mixture too lean.

Adjust carburettors.

Generator does

1. Open or short in lead wires, or loose lead

Repair or replace or

not charge

connections.

retighten.

2. Shorted, grounded or open generator coils.

Replace.

3. Shorted or defective regulator/rectifier.

Replace.

Generator charges,

1. Lead wires tend to get shorted or open-circuited or

but charging rate is

loosely connected at terminals.

Repair or retighten.

below the

2. Grounded or open-circuited stator coils of generator.

Replace.

specification

3. Defective regulator/rectifier.

Replace.

4. Defective battery.

Replace.

Generator

1. Internal short-circuit in the battery.

Replace the battery.

overcharges

2. Regulator/rectifier damaged or defective.

Replace.

3. Regulator/rectifier poorly grounded.

Clean and tighten
ground connection.

Unstable charging

1. Lead wire insulation frayed due to vibration, resulting

in intermittent shorting.

Repair or replace.

2. Generator internally shorted.

Replace.

3. Defective regulator/rectifier.

Replace.

ELECTRICAL SYSTEM

8 - 11

M

SERVICING INFORMATION

Complaint

Symptom and possible causes

Remedy

Battery runs down

1. The charging system is defective.

Check the generator, 

quickly

regulator/rectifier and
circuit connections,
and make necessary
adjustments to obtain
specified charging
operation.

2. Cell plates have lost much of their active

Replace the battery,

material as a result of over-charging.

and correct the
charging system.

3. A short-circuit condition exists within the battery

due to excessive accumulation of sediments caused
by the incorrect electrolyte.

Replace the battery.

4. Battery is too old.

Replace the battery.

Reversed battery

The battery has been connected the wrong way round

Replace the battery

polarity

in the system.

and be sure to connect
the battery properly.

Battery discharges

1. Dirty container top and sides.

Clean.

too rapidly

2. Battery si too old.

Replace.

BATTERY

Complaint

Symptom and possible causes

Remedy

Insufficient brake

1. Leakage of brake fluid from hydraulic system.

Repair or replace.

power

2. Worn pads.

Replace.

3. Oil adhesion on engaging surface of pads.

Replace.

4. Worn disc.

Replace.

5. Air in hydraulic system.

Bleed air.

Brake squeaking

1. Glazed pad surface.

Repair surface with
sandpaper.

2. Tilted pad.

Modify pad fitting.

3. Damaged wheel bearing.

Replace.

4. Loose front-wheel axle or rear-wheel axle.

Tighten to specified
torque.

5. Worn pads.

Replace.

6. Foreign material in brake fluid.

Replace brake fluid.

7. Clogged return port of master cylinder.

Disassemble and clean
master cylinder.

Excessive brake

1. Air in hydraulic system.

Bleed air.

lever stroke

2. Insufficient brake fluid.

Replenish fluid to
specified level;
bleed air.

3. Improper quality of brake fluid.

Replace with correct
fluid.

Leakage of brake fluid

1. Insufficient tightening of connection joints.

Tighten to specified
torque.

2. Cracked hose.

Replace.

3. Worn piston and/or cup.

Replace piston and/
or cup.

BRAKES

SERVICING INFORMATION

M

8 - 12

Complaint

Symptom and possible causes

Remedy

Heavy steering

1. Steering stem nut overtightened.

Adjust.

2. Broken bearing in steering stem.

Replace.

3. Distorted steering stem.

Replace.

4. Not enough pressure in tyres.

Adjust.

Wobbly handle

1. Loss of balance between right and left front forks.

Adjust.

2. Distorted front fork.

Replace.

3. Distorted front axle or crooked tyre.

Replace.

Wobbly front wheel

1. Distorted wheel rim.

Replace.

2. Worn-down front wheel bearings.

Replace.

3. Defective or incorrect tyre.

Replace.

4. Loose nut on axle.

Retighten.

5. Incorrect front fork oil.

Adjust.

Front suspension

1. Weakened springs.

Replace.

too soft

2. Not enough fork oil.

Refill.

Front suspension

1. Fork oil too viscous.

Replace.

too stiff

2. Too much fork oil.

Drain excess oil.

Noisy front

1. Not enough fork oil.

Refill.

suspension

2. Loosen nuts on suspension.

Retighten.

Wobbly rear wheel

1. Distorted wheel rim.

Replace.

2. Worn-down rear wheel bearings or

swingarm bearings.

Replace.

3. Defective or incorrect tyre.

Replace.

4. Worn swingarm and rear cushion related bearings.

Replace.

5. Loose nuts or bolts on rear suspension.

Retighten.

Rear suspension

1. Weakened shock absorber spring.

Replace.

too soft

2. Rear suspension adjuster improperly set.

Adjust.

3. Oil leakage of shock absorber.

Replace.

Rear suspension

1. Rear suspension adjuster improperly set.

Adjust.

too stiff

2. Shock absorber shaft bent.

Replace.

3. Swingarm bent.

Replace.

4. Worn swingarm and rear cushion related bearings.

Replace.

Noisy rear suspension

1. Loose nuts or bolts on rear suspension.

Retighten.

2. Worn swingarm and rear cushion related bearings.

Replace.

CHASSIS