Stihl 038 - Guide Bar, Chain and Sprocket; Guide bar; Breaking in Oilomatic chain; Chain lubrication

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Guide Bar, Chain and Sprocket
Guide bar
The nose and underside of the guide bar are subject toa
particularly high rate of wear. To avoid one-sided wear,
turn the bar over every time you resharpen or replace the
chain. Regular cleaning of the oil inlet holes and guide bar
groove is also important. The bar can be examined for
signs of wear at the same time.
A minimum bar groove depth must be maintained in order
to prevent the drive links contacting the bottom of the
groove (the heels of the cutter and tie strap would no
longer ride on the guide bar rails). The groove depth varies
according to chain type and pitch:
Chain type Chain pitch Minimum depth
Rapid 3/8” 6.0 mm (0.24”)
Topic 3/8” 6.5 mm (0.26”)
The groove depth should be measured at the point where
the bar is stressed most. That is the bar nose on Duromatic
bars and the area where most of the cutting is done on
Rollomatic bars. The guide bar must be replaced when
groove depth is less than the specified minimum.
On Rollomatic guide bars it is not necessary to separately
lubricate the sprocket nose bearing because the chain oil
which flows to the bearing by way of the bar groove during
normal operation is adequate for lubrication.
Checking chain lubrication
Breaking in Oilomatic chain
Every new chain has to be broken in for about 2 to 3 minu-
tes. Ample chain lubrication is essential during this period.
After breaking in, stop the engine, check chain tension and
adjust if necessary.
Chain lubrication
Never operate the chain saw without proper chain lubrica-
tion. If the chain is allowed to run dry the whole cutting
attachment will be irretrievably damaged within a very
short time. For this reason you should always check
operation of the chain lubricating system and the level in
the oil tank before starting work.
Start the saw and hold the cutting attachment over a light
patch of ground. Take care — the Oijlomatic chain must not
touch the ground; hold it at least 20 cm (8 in) clear of the
ground. Run the engine at about half throttle. If an increas-
ing film of oil can be seen on the ground, chain lubrication
is operating correctly.