Clutch, Chain Drive, Chain Brake And Chain Tensioner; Clutch Drum/Chain; Sprocket - Stihl MS 290 Manual

5.

Clutch, Chain Drive, Chain Brake and Chain Tensioner

5.1 Clutch Drum/Chain Sprocket
– Remove the chain sprocket
cover.
: Disengage the chain brake by
pulling the hand guard towards
the front handle.
1
2
: Remove the E-clip (1).
: Remove the washer (2).
– If a rim sprocket is fitted, pull it off.
: Remove the clutch drum/chain

sprocket.

14
: Remove the needle cage.
– Clean the clutch drum/chain
sprocket with standard solvent-
based degreasant containing no
chlorinated or halogenated
hydrocarbons, b 13.
!
80%
: Inspect the clutch drum (1) for
signs of wear.
If there are signs of serious wear on
the inside diameter of the clutch
drum (1), check the remaining wall
thickness. If it is less than about
80% of the original thickness, fit a
new clutch drum.
If the clutch drum has to be
replaced, also check the brake
band, b 5.6.2
: If the clutch drum/chain sprocket
is still serviceable, use No. 120
emery paper or emery cloth
(grain size approx. 120 µm) to
clean and roughen its friction
surface.
Install in the reverse sequence.
– Clean crankshaft stub with
standard solvent-based
degreasant containing no
1
chlorinated or halogenated
hydrocarbons. Wash needle
cage and lubricate with grease,
b 13.
100%
– Replace damaged needle cage.
MS 290, MS 310, MS 390