29Chain and Bar Manual
3.17.5 Checking Chain
Lubrication
Chain lubrication must be checked
before starting work and at regular
intervals during cutting.
Hold the bar nose over a light
background (tree stump, sawdust,
etc.) with the chain running. Chain
lubrication is in order if an
increasing trace of oil can be seen
against this background. The oil
flow rate is adequate if the sides of
the saw chain are always coated
with an unbroken oil film.
Different oil flow requirements
The amount of chain oil required
differs according to the application.
Long guide bars, large trunk
diameters, hard and dry woods as
well as thick barks need more chain
lubricating oil, while short guide
bars, soft and damp woods need
less. In order to meet these different
requirements, STIHL medium-duty
and heavy-duty saws are equipped
with a variable-flow oil pump.
Smoking in cut
If the cutting attachment begins to
smoke in the cut and/or the chain
snags in the bar groove, the reason
is overheating. This may be caused
by inadequate lubrication. Other
possible causes are a dull or
incorrectly sharpened chain or, on
Duromatic bars, an over-tensioned
chain. All three possibilities must be
investigated and corrected as
necessary.
3.17.6 STIHL OILOMATIC
®
Principle
Chain lubrication has the greatest
influence on the service life of a
chain.
The patented OILOMATIC
®
principle of chain lubrication
extends the useful life of the saw
chain.
Unlike conventional chains, each
drive link of STIHL OILOMATIC
®
saw chain incorporates an oil
channel (1) which slopes upwards
from the center of the drive link tang.
The inertial and centrifugal forces
created as the chain travels around
the bar cause the lubricating oil in
the bar groove to be forced up
through the oil channel. It is
conveyed outwards to those places
where lubrication is needed most.
The oil reservoir (2) integrated in
the drive link improves lubrication at
the bar nose and the bottom of the
bar in particular.
Lubricating oil collects in the
dimples (3) on both sides of the
drive link. This minimizes sliding
friction, optimizes lubrication and
reduces wear.
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