
Lawnmower problems
The engine brake cable is
faulty or unfastened
Electrical problems
The microswitch is faulty
Electric current does not reach
the spark plug
Engine block problems
Fouling in the combustion
chamber
Insufficient pressure
Lawnmower problems
The lawnmower blade is loose
Intake problems
Air filter is clogged up
The cable control does not activate the coil earth
switch.
If the microswitch remains locked in the pressed
position, it does not stop the coil earth connec-
tion.
The spark plug is badly connected, faulty or the
electrodes are too far away.
The coil is faulty and does not supply current or
the air gap is too large.
Fouling in the combustion chamber absorbs the
fresh mixture, which makes starting difficult and
may impair valve closure.
The cylinder head screws can loosen causing
the gasket to burn.
The piston rings can wear out due to the pas-
sage of dust caused by an excessively dirty or
unoiled air filter or overheating due to the lack of
oil.
The loose blade stops the effect of the flywheel
and the kick-back can make starting difficult.
The clogged filter can thicken the mixture flood-
ing the engine.
Adjust and/or replace
the cable
Replace the
microswitch
Check the spark plug
and the efficiency of
the ignition system
with the spark test
[
Dismount the cylinder
head and remove foul-
ing
Dismount the cylinder
head and replace the
gasket
Change the engine
[
Check that the lawn-
mower blade and hub
are securely fastened
Check and clean the
air filter
01/2005
SV 150
5.1
.
0
TROUBLESHOOTING
1 / 5
WORKSHOP MANUAL
page
from
2004
to
••••
A) The engine does not start
Probable cause
Comment
Solution
B) The engine starts badly or kicks back
Probable cause
Comment
Solution