19Series 4180 Powerhead
Dirty air filters reduce engine power, 
increase fuel consumption and 
make starting more difficult.
The air filter must be cleaned when 
there is a noticeable loss of engine 
power.
– Close the choke shutter.
– Clean away any loose dirt from 
around the filter and filter cover.
: Loosen the slotted screw (1) and 
lift away the filter cover.
1
: Remove the filter (1).
The filter element is not washable. If 
it is heavily loaded with dirt, fit a new 
one.
1
: Take out the screws (1 and 2).
– Remove the air filter housing.
VA
21
: Remove the paper gasket (1) and 
fit a new one.
When reassembling, check that the 
air filter housing is of the right type:
VA
1
: Air filter housing (A) without stub 
for tank vent without return line, 
b
6.5
: Air filter housing (B) with stub 
(arrow) for tank vent with return 
line to clean air side, b
6.5
Install air filter housing (B) with stub 
only with the connecting hose to the 
tank vent.
Unfiltered air would be sucked in if 
the connecting hose is not fitted. 
This would result in an increased 
rate of wear and a risk of engine 
damage.
Reassemble all other parts in the 
reverse sequence.
– Tighten down screws on air filter 
housing, b
3.4
– Tighten down screw air on filter 
cover, b
3.4
6. Fuel System
6.1 Air Filter