Engine - Stihl 020 T Service Manual

2.2

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
STIHL 020 T
Cause
Oil seals in crankcase
damaged
Manifold leaking
Cylinder base gasket leaking
Crankcase damaged (cracks)
Secondary air seepage through
poorly mounted or faulty manifold
Piston rings leaking or
broken
Muffler carbonized
Insufficient cylinder cooling.
Air inlets in fan housing
blocked or cooling fins on
cylinder very dirty
Remedy
Replace oil seals
Seal or replace manifold
Replace gasket
Replace crankcase
Mount manifold correctly or
replace
Fit new piston rings
Clean muffler (inlet and
exhaust), replace spark
arresting screen (if fitted)
Thoroughly clean all cooling air
openings and cylinder fins
7