Husqvarna 250PS - Manual (Page 8)

8
– English
SAFETY INSTRUCTIONS
Sharpening your chain and
adjusting raker clearance
WARNING!
The risk of kickback is increased with a
badly sharpened chain!
Specification of blade and chain
When the cutting equipment supplied with your saw
becomes worn or damaged you will need to replace it. Use
only the type of bar and chain recommended by us.
A. General information on sharpening
cutting teeth
• Never use a blunt chain. When the chain is blunt you have
to exert more pressure to force the bar through the wood
and the cuttings will be very small. If the chain is very blunt
it will not produce any cuttings at all, just wood powder.
• A sharp chain eats its way through the wood and produces
long, thick cuttings.
• The cutting part of the
chain is called the
CUTTING LINK and
this consists of a
CUTTING TOOTH
(A) and the RAKER LIP
(B). The cutting depth is
determined by the
difference in height
between the two.
• When you sharpen a
cutting tooth there are
five important
factors to remember:
FILING ANGLE
CUTTING ANGLE
FILE POSITION
ROUND FILE DIA-
METER
FILE DEPTH
Guide bar
• Length (inches/cm)
• Number of teeth on bar
tip sprocket (T).
Small number = small tip
radius = low-kickback
• Chain pitch (inches)
The spacing between the
drive links of the chain
must match the spacing of
the teeth on the bar tip
sprocket and drive
sprocket.
• Number of drive links
The number of drive links
is determined by the
length of the bar, the
chain pitch and the
number of teeth on the
bar tip sprocket.
• Bar groove width (inches/
mm)
The groove in the bar
must match the width of
the chain drive links.
• Saw chain oil hole and
hole for chain tensioner
The bar must be matched
to the chain saw design.
!
B
A
1
5
Saw chain
• Saw chain pitch (inches)
Spacing between drive
links.
• Drive link width (mm/
inches)
• Number of drive links
• Level of kickbak
reduction
The level of kickback
reduction offered by a
chain is indicated by its
model number.