14 Series 4144 Components FC, FS, KM
4.5 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 Cause Remedy
Engine does not start easily, stalls 
at idle speed, but operates normally 
at full throttle
Oil seals in crankcase damaged Replace the oil seals
Crankcase leaking or damaged 
(cracks)
Seal or replace the crankcase
Engine does not deliver full power 
or runs erratically
Piston ring worn or broken Fit new piston ring
Muffler / spark arresting screen 
carbonized
Clean the muffler (inlet and 
exhaust), replace spark arresting 
screen, replace muffler if necessary
Air filter dirty Replace air filter
Fuel hose kinked or torn Fit new hose or position it free from 
kinks
Engine overheating Insufficient cylinder cooling. Air 
inlets blocked or cooling fins on 
cylinder very dirty 
Thoroughly clean all cooling air 
openings and the cylinder fins