User Manual

0478 111 9943 A - EN
48
Information on compliance with the
REACH Directive (EC) No. 1907/2006 is
available from www.stihl.com/reach.
Fault:
Engine not starting
Possible cause:
– Motorstop lever not pressed.
– No fuel in tank.
– Fuel line blocked.
– Inferior, dirty or old fuel in tank.
– Air filter dirty.
– Spark plug socket detached from spark
plug; ignition lead not properly fastened
to socket.
– Spark plug dirty or damaged; incorrect
electrode gap.
Remedy:
– Press motorstop lever to handlebar and
hold. (Ö 9.1)
– Refill fuel tank. (Ö 7.6)
– Clean fuel line. , #
– Always use fresh, good quality fuel,
unleaded petrol; clean
carburettor. , #
– Clean air filter. , #
– Connect spark plug socket; check
connection between ignition lead and
socket. , #
– Clean or replace spark plug; adjust
electrode gap. #
Fault:
Starting problems or deteriorating engine
power.
Possible cause:
– Lawn mower housing blocked.
– Mowing at an excessively low cutting
height or propulsion speed is too high in
relation to the cutting height.
– Water in fuel tank and carburettor;
carburettor blocked.
– Fuel tank contaminated.
–Air filter dirty.
– Spark plug dirty.
Remedy:
– Clean lawn mower housing (detach
spark plug socket!). (Ö 12.1)
– Select a higher cutting height or reduce
the pushing speed. (Ö 8.5)
– Empty fuel tank, clean fuel line and
carburettor. #
– Clean fuel tank. #
– Clean air filter. #
– Clean spark plug. #
Fault:
Engine overheating.
Possible cause:
– Oil level in engine too low.
– Cooling ribs dirty.
Remedy:
– Change engine oil. (Ö 7.6)
– Clean cooling ribs. (Ö 12.1)
Fault:
Excessive vibration during operation.
Possible cause:
– Cutting unit defective.
– Engine mounting loose.
Remedy:
– Check mowing blade, blade shaft and
blade fastening (blade fastening screw
and retaining washer), and repair if
necessary. #
– Tighten engine mounting bolts. #
Fault:
No drive when self-propulsion lever is
actuated. (RM 4 RT, RM 4 RT,
RM 4 RTP)
Possible cause:
– Self-propulsion cable damaged
(e.g. kinked)
Remedy:
– Replace cable #
Fault:
Poor cut, lawn turning yellow
Possible cause:
– Mowing blade is blunt or worn,
Remedy:
– Sharpen or replace the mowing blade
(Ö 12.3), (Ö 12.4), #
19. Troubleshooting
# If necessary, contact a specialist
dealer; STIHL recommends STIHL
specialist dealers.
@ See engine instruction manual.