Specifications

23MS 290, MS 310, MS 390
– Remove the chain sprocket
cover.
: Take out the screw (arrow).
– Pull tensioner assembly out of
the engine housing.
VA
135RA044
: Take the thrust pad (1) off the
adjusting screw (2).
: Rotate the spur gear (3) until the
adjusting screw comes out of the
tensioner slide (4).
VA
135RA045
1 4 2 3
: Pull the spur gear out of the
cover.
VA
135RA046
: Pull the tensioner slide off the
cover.
– Take the adjusting screw out of
the cover.
– Inspect the teeth on the spur gear
and adjusting screw. Replace
VA
135RA047
both parts if necessary.
Install in the reverse sequence.
– Coat teeth of adjusting screw and
spur gear with grease, b 13,
before refitting.
This machine does not have a
conventional crankcase. The
engine consists of the cylinder,
piston, crankshaft and engine pan.
– Troubleshooting, b 4.6
: Unscrew the nuts (arrows).
VA
209RA020
: Remove the conical spring
washers (arrows).
: Remove the cover (1).
VA
209RA021
1
5.8 Chain Tensioner 6. Engine
6.1 Muffler/Spark Arresting
Screen