Pressure Test; Oil Seals - Stihl MS 650 Manual

6.3.3

Pressure Test

– Preparations – b 6.3.1
: Connect pressure hose (1) of
tester 1106 850 2905 to nipple
(arrow) on test flange.
: Close vent screw (1) on the
rubber bulb.
: Pump air into the crankcase with
rubber bulb until the gauge
(arrow) indicates a pressure of
0.5 bar. If this pressure remains
constant for at least 20 seconds,
the crankcase is airtight.
32
– However, if the pressure drops,
the leak must be located and the
faulty part replaced.
To find the leak, coat the suspect
area with oil and pressurize the
crankcase. Bubbles will appear if a
leak exists.
– After finishing the test, open the
vent screw and disconnect the
hose of tester 1106 850 2905.
– Remove the test flange.
– Install the carburetor – b 12.2.1
– Loosen the muffler bottom casing
screws and remove the sealing
plate.
– Take out the screws one at a time
and refit with Loctite – b 17
1
– Tighten down the screws firmly –
b 3.5
– Mount the muffler top casing.
– Unscrew the plug from the
cylinder.
– Install the decompression valve –
b 6.8
Reassemble all other parts in the
reverse sequence.
6.4

Oil Seals

It is not necessary to disassemble
the complete crankcase to replace
the oil seals.
Flywheel side
– Remove the flywheel –
b 7.3.1
: Remove the key (arrow) from the
crankshaft.
1
1
2 1
: On machines with handle/
carburetor heating, take out the
screws (1).
: Remove the generator (2).
MS 650, MS 660