11.3.2 Servicing; Fuel System; Air Filter - Stihl MS 650 Manual

11.3.2 Servicing

5
4 7 3
7 6
Always check the suction hose and
pickup body before disassembling
the oil pump.
– Remove the oil pump – b 11.3.1
: Use a 2 mm drift to drive out the
spring pin (1).
: Pull out the control bolt (2).
: Remove the O-rings (3).
: Pry out the plug (4).
: Remove the pump piston (5) with
spring (6) and washers (7).
– Clean all parts and examine for
serviceability – b 17
Always install new O-rings.
– Lubricate the pump piston and
worm with grease before
installing – b 17
: When fitting the control bolt (2),
press in the plug (4) against
spring pressure.
Reassemble in the reverse
sequence.
MS 650, MS 660
12.

Fuel System

12.1

Air Filter

Dirty air filters reduce engine power,
1
increase fuel consumption and
make starting more difficult.
The air filter should be cleaned
when there is a noticeable loss of
engine power.
2
1
2
: Unscrew the twist lock (1).
: Remove the filter cover (2).
1
: Pull off the air baffle (1) vertically.
1
: Remove the air filter (1).
– Remove and clean the felt
prefilter (machines with HD air
filter).
– Knock out the filter or blow it clear
with compressed air from the
inside outwards.
– In case of stubborn dirt, wash all
parts of the filter in STIHL
universal cleaner or a fresh, non-
flammable cleaning solution (e.g.
warm soapy water) and allow to
dry.
– Do not use a brush to clean the
felt prefilter. Replace damaged
filters.
1
: Pull off the baffle (1) in the
direction of the arrow.
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