YATO YT-84900 Manual Original página 22

GB
cutting downwards. (XIX)
Thus it is possible to minimise the risk of wedging the sawing machine during cutting.
7. MAINTENANCEA OF THE SAWING MACHINE
Before proceeding to any of the following activities turn the sawing machine off. Make sure the motor is cold.
Remove the spark plug so as to avoid accidental activation of the sawing machine.
During any work on the chain, wear protective gloves.
7.1. Replacement and maintenance of the spark plug (XX)
In order to replace the spark plug remove the air filter cover and the air filter.
Remove the rubber protection of the spark plug contact and the spark plug itself, using the supplied wrench.
Check the electrodes of the spark plug. If they are soiled, try to clean the electrodes with a wire brush. If they cannot be cleaned,
replace the spark plug. Check the spark plug at least once a month.
7.2. Maintenance of the air filter (XXI)
Maintenance of the air filter must be carried out after each use of the sawing machine.
Dust and major dirt may be removed from the filter knocking the frame of the filter slightly against a hard surface.
Clean the filter mesh separating the halves of the filter and rinsing the mesh in extraction petrol. Use compressed air jet to blow
dirt from the mesh.
7.3. Maintenance and cleaning of the oil system (XXII)
Cleaning of the oil slot and the oil grove of the guide must be realised after each use of the sawing machine.
Remove the side panel and the guide, and check the conditions of the oil groove and remove any dirt.
Remove the chain from the guide. Clean the guide from chips and dirt. Clean the chain guide groove and the oil feeding orifice.
Lubricate the toothed wheel at the top of the guide, using a couple of drops of oil through the lubricating hole.
The chain guide groove wears out during work. Turn the guide periodically and check the form of the groove. If the shape of the
groove is like in the drawing (XXIII), the guide must be replaced.
Wearing of the groove may be inspected placing a ruler to the guide with the chain. If the ruler does not adhere to the guide, then
the groove is in good conditions. Otherwise the guide should be replaced.
7.4. Other maintenance actions
After each use check also the general conditions of the sawing machine. Tighten loose bolted connections. Check for fuel and oil
leakage. Check is the ventilation slots are clean. Check if all the protections and housings are in good conditions and free from
cracks. Before further work eliminate all the detected defects.
7.5. Maintenance of the cylinder ribs (XXIV)
Dirt accumulated between the cylinder ribs may lead to overheating of the motor. Clean the areas between the cylinder ribs
periodically. In order to do so remove the air filter cover, the air filter and the spark plug. Then remove the bolts and the cylinder
protection. Clean the area between the cylinder ribs and assembly the sawing machine, paying attention to the position of the
electrical cables and other conductors.
7.6. Chain driving wheel
Check the conditions of the chain driving wheel periodically. In case it is worn out, cracked or damaged in a way that may lead to
incorrect functioning of the drive transfer system, the driving wheel must be replaced in an authorised repair workshop.
Do not install a worn out chain on a new driving wheel or a new chain on a worn out driving wheel.
7.7. Maintenance of the chain
The chain must be always sharp and in good conditions. Before each use check the chain for wear – whether its links are not
damaged and the sprockets broken. In case any defects are detected, it is prohibited to continue working with the chain. This
might lead to serious injuries.
The chain must be periodically sharpened. Sharpening is necessary if any of the following is observed: sawdust generated during
cutting resembles dust, it is necessary to apply additional force for cutting, the cuts are not straight, vibrations or fuel consumption
increase.
Sharpening requires special tools and adequate experience. Therefore it must be realised in specialised service points.
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