Guide Bar Maintenance - Stiga SP 386 Gebrauchsanweisung

– the cut is not straight.
– vibrations increase.
– fuel consumption increases.
Kickback may occur if the chain
is not sufficiently sharpened
IMPORTANT It is recommended to have a
specialised centre sharpen the chain using the
right tools to ensure minimum removal of material
and even sharpness on all the cutting edges.
8.7.1 Chain sharpening
If you sharpen the chain yourself, use special
round-section files with the right diameter
depending on the type of chain (see "Chain
Maintenance Table ", chap. 14). You need
a certain amount of skill and experience
to avoid damaging the cutting edges.
Sharpen the chain as follows:
1. Stop the machine (par. 6.6).
2. Disengage the chain brake (par. 5.7)
3. Secure the bar with the chain in a vice (Fig.
43.A), so that the chain can run smoothly.
4. Tighten the chain if it is loose (par. 6.1.3).
5. Insert the file in the tooth at a constant
angle from the cutting edge (Fig.
43.B). Using a sharpening plate makes
using the file easier (Fig. 43.C).
6. Sharpen in a forward motion a few times
and repeat this on all the cutting edges
facing the same way (right or left).
7. Turn the bar over in the vice and repeat
on all the other cutting edges.
8. Check that the limiter tooth (Fig. 43.D)
complies with the levels indicated in
the "Chain Maintenance Table" (chap.
14) and file any projecting parts with
a flat file, rounding off the edge.
9. After sharpening, remove all traces of filing
and dust and lubricate the chain in an oil bath.
8.7.2 Replacing the toothed chain
Replace the chain when:
– the length of the cutting edges
reduces to 5 mm or less (Fig. 43.E);
– there is too much play between
the links and the rivets.
– the cutting speed is too slow and the
repeated sharpening does not improve
the cutting speed. The chain is worn.
IMPORTANT After replacing the chain,
its tension level must be checked more
frequently due to settling of the chain.

8.8 GUIDE BAR MAINTENANCE

NOTE Any work on the guide bar requires
specific experience and special tools in order
to achieve top workmanship standards; for
safety purposes, we recommend you contact
your dealer to ensure work is done correctly.
To avoid asymmetrical wear on the bar,
make sure it is turned over periodically.
To keep the bar in perfect working
order, proceed as follows:
1. Grease the bearings on the nose sprocket
(if present) with the syringe (not included).
2. Clean the bar groove with the scraper
(not included) (Fig. 44.A);
3. Clean the lubrication holes (Fig. 44.B);
4. With a flat file (not included), remove burr
from the edges and level off the guides.
(.
8.8.1 Replacing the bar
Replace the bar whenever:
– the groove is not as deep as the
height of the drive links (which
must never touch the bottom);
– the inside of the guide is worn enough
to make the chain lean to one side.
8.9 TUNING MINIMUM SPEED
If the cutting means moves when the
engine is running idle, contact your dealer
or Authorised Service Centre to have the
engine adjusted correctly (par. 8.11).
8.10 TUNING THE CARBURETTOR
The carburettor is tuned by the manufacturer
to achieve maximum performance in all
situations, with a minimum emission of toxic gas
in compliance with the regulations in force.
In the event of poor performance, contact
your Dealer or Authorised Service Centre
for a check of the carburetion and engine.
Carburettor tuning:
T = minimum speed tuning
L = low speed mixture tuning
H = high speed mixture tuning
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