13Series 4144 Powerhead
6. Engine
Removal and installation of the 
engine is described in the service 
manual for "Series 4144 
Components – FS, FC, KM".
6.1 Leakage Test
Defective oil seals and gaskets or 
cracks in castings are the usual 
causes of leaks. Such faults allow 
supplementary air to enter the 
engine and upset the fuel-air 
mixture.
This makes adjustment of the 
prescribed idle speed difficult, if not 
impossible.
Moreover, the transition from idle 
speed to part or full throttle is not 
smooth.
Always perform the vacuum test 
first and then the pressure test.
The engine can be checked 
thoroughly for leaks with the pump 
0000 850 1300.
The engine does not need to be 
removed for the leakage test.
6.1.1 Preparations
– Remove the fan housing – see 
service manual for "Series 4144 
Components – FS, FC, KM"
– Remove the spark plug boot with 
cap.
: Unscrew the spark plug (1).
– Set the piston to top dead center. 
This can be checked through the 
spark plug hole.
– Fit the spark plug (1) and tighten 
it down firmly.
– Tightening torques, b 3.3
: Loosen the screws (arrows).
– Lift the muffler (1).
938RA093 TG
1
938RA015 TG
1
: Fit the sealing plate (1) 
0000 855 8106 between the 
cylinder exhaust port and muffler 
and tighten down the screws 
moderately.
The sealing plate must completely 
fill the space between the two 
screws.
– Remove the carburetor 
– see service manual for 
"Series 4144 Components – FS, 
FC, KM"
Check that the gasket (1) is in 
position.
938RA016 TG
1
938RA017 TG
1