O-Mac MF 2500 Manual page 65

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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