Operating Instructions; Taking Care Of The Guide Bar - Stihl HT 105 Owner's Instruction Manual

Operating Instructions

During Break-In Period
A factory-new machine should not be
run at high revs (full throttle off load) for
the first three tank fillings. This avoids
unnecessary high loads during the
break-in period. As all moving parts
have to bed in during the break-in
period, the frictional resistances in the
engine are greater during this period.
The engine develops its maximum
power after about 5 to 15 tank fillings.
During Operation
NOTICE
Do not make the mixture leaner to
achieve an apparent increase in power –
this could damage the engine – see
"Adjusting the Carburetor."
Check chain tension frequently
A new chain has to be retensioned more
often than one that has been in use for
some time.
Chain cold
Tension is correct when the chain fits
snugly against the underside of the bar
and can still be pulled along the bar by
hand. Retension if necessary – see
"Tensioning the Saw Chain."
HT 105, HT 134, HT 135
Chain at operating temperature
The chain stretches and begins to sag.
The drive links must not come out of the
bar groove – the chain may otherwise
jump off the bar. Retension the chain –
see "Tensioning the Saw Chain."
After long period of full-throttle operation
Allow engine to run for a short while at
idle speed so that engine heat can be
dissipated by the flow of cooling air. This
protects engine-mounted components
(ignition, carburetor) from thermal
overload.
After Finishing Work
Slacken off the chain if you have
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retensioned it at operating
temperature during cutting work.
NOTICE
Always slacken off the chain after
finishing work. The chain contracts as it
cools down. If it is not slackened off, it
can damage the gear shaft and
bearings.
Storing for a short period
Wait for the engine to cool down. Drain
the fuel tank. Store the machine in a dry
location. Check the tightness of all
accessible screws and nuts (not
adjusting screws) at regular intervals
and retighten if necessary.
Storing for a long period
See chapter on "Storing the Machine."

Taking Care of the Guide Bar

1
Turn the bar over – every time you
N
sharpen the chain and every time
you replace the chain – this helps
avoid one-sided wear, especially at
the nose and underside of the bar.
Regularly clean the oil inlet hole (1),
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the oilway (2) and the bar
groove (3).
Measure the groove depth – with the
N
scale on the filing gauge (special
accessory) – in the area used most
for cutting.
Chain type Chain pitch Minimum
groove depth
Picco 3/8" P 0.20"
(5.0 mm)
Picco 1/4" P 0.16"
(4.0 mm)
If groove depth is less than specified:
English
2
3
33