Engine - Stihl MS 270 User Manual

4.6

Engine

Always check and, if necessary,
repair the following parts before
looking for faults on the engine:
– Air filter
– Fuel system
– Carburetor
– Ignition system
Condition
Engine does not start easily, stalls
at idle speed, but operates normally
at full throttle
Engine does not deliver full power
or runs erratically
Engine overheating
16
Cause
Oil seals in crankcase damaged
Crankcase leaking or damaged
(cracks)
Muffler leaking
Piston rings worn or broken
Muffler/spark arresting screen
carbonized
Air filter element dirty
Fuel/impulse line severely kinked or
damaged
Decompression valve sticking
Insufficient cylinder cooling. Air
inlets in fan housing blocked or
cooling fins on cylinder very dirty
Remedy
Replace the oil seals
Seat or replace the crankcase
Replace the muffler
Fit new piston rings
Clean the muffler (inlet and
exhaust), replace spark arresting
screen
Replace air filter element
Replace lines or position them free
from kinks
Replace the decompression valve
Thoroughly clean all cooling air
openings and the cylinder fins
MS 270, MS 280