50 Series 4144 Components FC, FS, KM
: Carefully remove the gasket with 
pump diaphragm from the end 
cover.
: Carefully separate the pump 
diaphragm (1) and gasket (2).
The diaphragm material is 
subjected to continuous alternating 
stresses and eventually shows 
signs of fatigue, i.e. the diaphragm 
distorts and swells and has to be 
replaced.
– Check the pump diaphragm for 
signs of damage and wear. Install 
a new gasket.
– Check fuel strainer for 
contamination and damage. 
Clean or replace if necessary. 
296RA247 TG296RA248 TG
2
1
: Use a needle to remove the fuel 
strainer (1) from the carburetor 
body. 
– Reassemble in the reverse 
sequence.
: Fit the gasket (1) so that the 
contours (arrows) match and it is 
held in position by the pegs (2).
: Fit the diaphragm on the gasket 
(1) so that the contours (arrows) 
match and it is held in position by 
the pegs (2).
545RA195 TG
1
296RA250 TG
2
1
2
296RA251 TG
1
2
2
– Position the end cover (1) so that 
the idle speed screw (arrow) is at 
the same side as the adjusting 
screws.
: Turn lever (2) on throttle shaft a 
little and place the end cover (1) 
against the carburetor body from 
below so that the gasket and 
pump diaphragm remain in 
position on the end cover.
– Align the end cover (1) so that its 
pegs engage the holes in the 
carburetor body.
– Check that diaphragm and 
gasket are properly seated.
: Tighten down the screw (1) 
firmly.
– Tightening torques, b 3.4
– Reassemble all other parts in the 
reverse sequence.
545RA196 TG
1
2
545RA197 TG
1