APRILIA Pegaso 650 Manual De Taller página 288

REPAIRS
8.1 TROUBLE-SHOOTING
8.1.1 ENGINE
For further information see ENGINE SERVICE MANUAL No 933 (D-UK) / No 934 (I-E-F).
DEFECT
Engine does not start or
starts with difficulty.
Engine stops too
frequently.
Engine idles with
difficulty.
Engine does not reach
maximum rpm.
Dirty or oily exhaust
gases.
8 - 16
SYMPTOM AND POSSIBLE CAUSE
Insufficient compression.
1) Insufficient valve clearance.
2) Fault camshaft timing.
3) Valves or valve guides worn or valve seats defective.
4) Decompressor off too late.
5) Piston segments worn.
6) Cylinder bore worn.
7) Excessive clearance between pick-up and rotor.
8) Spark plugs loose.
9) Starter does not run, or runs intermittently.
No spark on spark plug.
1) Dirty spark plug.
2) Damp spark plug.
3) Faulty ignition system.
4) Ignition coil or spark plug cable defective.
5) Ignition system in short circuit.
Fuel does not reach carburettor.
1) Vent hole clogged on tank cap.
2) Fuel filters clogged or defective.
3) Needle valve of carburettor defective.
4) Fuel system pipes clogged.
5) Fuel pump defective.
1) Spark plug dirty.
2) Ignition system defective.
3) Fuel system pipes clogged.
4) Carburettor jets clogged.
5) Air cleaner clogged.
6) Fuel filters clogged.
1) Insufficient valve clearance.
2) Valve guide worn or valve seats defective.
3) Decompressor off too late.
4) CO content too low at idling.
5) Infiltrations of air from intake flange.
6) Excessive gap between spark plug electrodes. .
7) Ignition system faulty.
8) Fuel supply insufficient.
1) Insufficient spark plug gap.
2) Jets clogged.
3) Faulty ignition coil.
4) Faulty ignition system.
5) Fuel level in carburettor float chamber too low.
6) Clogged air cleaner.
7) Fuel pipes clogged, resulting in scarce flow of fuel to carbu-
rettor.
1) Sealing elements, valve guides, scraper rings and gaskets
worn or damaged.
2) Any porosity
REMEDY
Adjust valve clearance.
Adjust.
Change valve guide, valve
seats.
Check free movement of
decompressor, replace
decompressor spring.
Replace segments.
Replace cylinder.
Adjust clearance.
Tighten spark plug.
C h e c k f r e e w h e e l ,
change.
Clean spark plug.
Clean and dry spark plug.
Check rotor, stator, and
unit, change faulty compo-
nent.
Change.
C h e c k c i r c u i t , c h a n g e
commutator.
Clean.
Clean or replace.
Change.
Clean.
Clean or replace.
Clean.
Repair or replace.
Replace.
Clean.
Clean.
Clean or replace.
Adjust valve clearance.
Change valve guides, low-
er valve seats.
Check easy movement of
decompressor, change
decompressor spring.
Check carburettor and jets
(clogged).
Change flange.
Change spark plug.
Check rotor, stator. and
unit, change defective
component.
Check.
Adjust.
Clean.
Change.
Repair or change.
Adjust.
Clean.
Clean and top up.
Check.
Check.