Stihl 088 - Tank Vent Valve and Spur Gear Service

STIHL 088 44
9.2
V
alve 9.3 S
p
ur Gea
r
A valve is installed in the tank wall
to keep internal tank pressure
equal to atmospheric pressure.
Cleaning the valve
- Unscrew the oil filler cap.
- Drain the oil tank.
Note: Collect chain oil in a clean
container or dispose of it properly
at an approved disposal site.
- Remove the inner side plate -
see 3.3.1.
- Blow valve clear with com -
pressed air - from outside to
inside of tank.
- Flush out the oil tank.
- Fit the inner side plate -
see 3.3.2.
- Refit the oil tank filler cap.
Replacing the valve
- Unscrew the oil filler cap.
- Remove the inner side plate -
see 3.3.1.
• Apply a drift from outside and ca-
refully drive the vent valve out of the
crankcase and remove it from the oil
tank.
• If necessary, remove the drive
spring from the worm.
Reassemble in the reverse
sequence.
• Use a 7 mm (9/32") drift to care-
fully press in the new valve until it
is about 1.0 mm (3/64") below the
face of the crankcase.
- Refit the inner side plate -see
3.3.2.
- Fit the oil filler cap.
- Remove the clutch - see 3.2.
• Pull the worm with drive spring
out of the oil pump and off the
crankshaft stub.