Husqvarna SM 50 / 2011, Workshop Manual

Page: 81 / 150

F.15
Ed. 01-09-2010
ENGINE
Piston installation clearance
LC engine : 0.045 - 0.055 mm (0.0015 - 0.0021 in)
REF. PISTON LC CYLINDER
A
39.455 - 39.460 mm
1.553 - 1.554 in
39.505 - 39.510 mm
1.555 - 1.556 in
B
39.461 - 39.465 mm
1.5536 - 1.5537 in
39.511 - 39.515 mm
1.5556 - 1.5557 in
C
39.466 - 39.470 mm
1.5538 - 1.5539 in
39.516 - 39.520 mm
1.5557 - 1.5559 in
D
39.471 - 39.475 mm
1.554 - 1.5541 in
39.521 - 39.525 mm
1.5559 - 1.5561 in
When changing piston and cylinder, make sure that they bear the same
marking.
The corresponding marking (A - D) is stamped on piston crown and
cylinder skirt.
The tolerance limits of the relevant components are specified in the above
table.
Always make sure that an installation clearance of at least 0.045 mm (0.00177
in.) is present.
Centrifugal clutch overhaul
- Loosen TE screws (1) from clutch shoes (2), and remove them together
with spring packs (3) from clutch hub (4).
- Remove TE screws with bushings and spring packs from clutch shoes.
Spring packs consist of 14 Belleville washers (5), which shall be over-
stacked as shown in the picture.
- Between spring packs and shoes, there are washers (6) to be used for
clutch spring preloading.
Engagement rpm can be varied through spring packs preload. a preload increase
of 0.5 mm results in an engagement rpm increase of approx. 500 rpm.
- With engagement rpm, we mean the number of revolutions at which clutch
starts engaging, and the bike starts running.
- Check engagement rpm on the rev. counter and, if necessary, adjust it at
8,500 - 9,000 rpm.