Engine - Stihl BT 45 Manual

4.4

Engine

Always check and, if necessary,
repair the following parts before
looking for faults on the engine:
– Air filter
– Fuel system
– Carburetor
1)
– 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
1)
see "Series 4140 Powerhead" service manual
BT 45
Cause
Oil seals in crankcase faulty
Crankcase leaking / damaged
(cracks)
Muffler leaking
Piston rings worn or broken
Muffler / spark arresting screen
carbonized
Air filter element dirty
Fuel / impulse line kinked or
cracked
Insufficient cylinder cooling.
Air inlets in fan housing
blocked or cooling fins on
cylinder very dirty
Remedy
1)
Install new oil seals
Seal / replace the crankcase
Seal / replace the muffler
Install new piston rings
Clean muffler (inlet and
exhaust openings), replace
spark arresting screen (stub)
Fit new air filter element
Fit new lines or position
without kinks
Thoroughly clean all cooling air
passages and cooling fins
1)
1)
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