REPAIRS
8.1 TROUBLE-SHOOTING
8.1.1 ENGINE
MALFUNCTION
SYMPTOM AND POSSIBLE CAUSES
Engine does not start or
Insufficient compression.
starts with difficulty.
1) Excessive wear of the cylinder or of the piston segments.
2) Piston segment stuck in the seat.
3) Leakages from the case, cylinder or cylinder head.
4) Spark plug fastening insufficient.
5) Piston broken, cracked or damaged.
6) Driving shaft sealing ring worn.
No spark in the spark plug.
1) Spark plug dirty.
2) Spark plug wet.
3) Faulty coil.
4) H.V. cable broken or in short circuit.
5) Faulty ignition system.
Fuel does not reach carburettor.
1) Tank plug vent clogged.
2) Fuel pump filter clogged or faulty.
3) Carburettor needle valve faulty.
4) Fuel system pipes clogged.
5) Faulty fuel pump.
6) Fuel header tank clogged.
Engine stops too
1) Dirty spark plug.
frequently.
2) Faulty ignition system.
3) Fuel system pipes clogged.
4) Carburettor jets clogged.
5) Air cleaner clogged.
6) Fuel pump filter clogged.
Engine too noisy.
Noise seems to come from piston.
1) Piston or cylinder excessively worn.
2) Combustion chamber encrusted with deposits.
3) Piston pin or piston seats worn.
4) Piston segment seat worn.
5) Piston pin roller cage worn.
Noise seems to come from driving shaft.
1) Clinking of worn bearings.
2) Bench bearings worn or burnt.
3) Driving shaft bearing worn or burnt.
Engine idles with difficulty.
1) Excessive spark plug gap.
2) Faulty ignition coil.
3) Faulty ignition system.
4) Incorrect fuel level in carburettor float chamber.
5) Jets clogged.
Engine does not reach
1) Insufficient spark plug gap.
maximum rpm.
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 carburettor.
Dirty or oily exhaust gases.
1) Sealing elements, valve guides, scraper rings and gaskets worn or damaged.
2) Any porosity
Engine lacks power.
1) Piston or cylinder segments worn.
2) Spark plug gap incorrect or faulty ignition system.
3) Carburettor jets clogged.
4) Incorrect fuel level in carburettor float chamber.
5) Air cleaner clogged.
6) Air infiltration from intake pipe.
Engine overheats.
1) Fuel level in carburettor float chamber too low.
2) Air infiltrations from intake pipe.
3) Unsuitable engine oil.
4) Faulty cooling system.
8.1.2 CARBURETTOR
MALFUNCTION
SYMPTOM AND POSSIBLE CAUSES
Hard starting.
1) Starting jet clogged.
2) Starting duct clogged.
3) Air infiltration from seal between starter body and carburettor.
4) Starter shutter malfunctions.
5) Battery partially discharged.
Irregular running at idling
1) Idle jet clogged or slackened.
or low rpm.
2) Air infiltration from S.I.P.C. pipe of carburettor or starter.
3) Idle mixture outlet or by-pass clogged.
4) Starter shutter is not completely closed.
8
- 10
REMEDY
Change.
Repair or change.
Repair or change.
Tighten.
Change.
Change
Clean or change.
Clean and dry.
Change.
Change.
Repair or change.
Clean.
Clean or change.
Change.
Clean.
Clean.
Clean or change
Clean or change.
Repair or change.
Change.
Clean.
Clean.
Clean or change.
Change.
Clean.
Change.
Change.
Change.
Change.
Change.
Change.
Adjust.
Change.
Repair or change.
Adjust.
Clean.
Adjust.
Clean.
Change.
Repair or change.
Adjust.
Clean.
Clean and top up.
Check.
Check.
Change.
Adjust or change.
Clean.
Adjust.
Clean.
Tighten or change
Adjust.
Tighten or change.
Use engine oil prescribed.
See radiator section
REMEDY
Clean.
Clean.
Check and tighten.
Repair
Check and recharge.
Check and clean.
Check.
Check and clean.
Check and adjust
Capítulos
