English – 33
MAINTENANCE
• The filter can be cleaned more thoroughly by washing it in 
water and detergent.
An air filter that has been in use for a long time cannot be 
cleaned completely. The filter must therefore be replaced with 
a new one at regular intervals. A damaged air filter must 
always be replaced.
A JONSERED chain saw can be equipped with different types 
of air filter according to working conditions, weather, season, 
etc. Contact your dealer for advice.
Spark plug
The spark plug condition is influenced by:
• Incorrect carburettor adjustment.
• Wrong fuel mixture (too much oil).
• A dirty air filter.
These factors cause deposits on the spark plug electrodes, 
which may result in operating problems and starting 
difficulties.
• If the machine is low on power, difficult to start or runs 
poorly at idle speed: always check the spark plug first 
before taking any further action. If the spark plug is dirty, 
clean it and check that the electrode gap is 0.5 mm. The 
spark plug should be replaced after about a month in 
operation or earlier if necessary.
CAUTION! Always use the recommended spark plug type! 
Use of the wrong spark plug can damage the piston/cylinder.
Muffler
The muffler is designed to reduce the noise level and to direct 
the exhaust gases away from the operator. The exhaust 
gases are hot and can contain sparks, which may cause fire 
if directed against dry and combustible material.
Some mufflers are equipped with a special spark arrestor 
mesh. If your machine has this type of muffler, you should 
clean the mesh at least once a week. This is best done with a 
wire brush.
CAUTION! The mesh must be replaced if it is damaged. If the 
mesh is blocked the machine will overheat and this will cause 
damage to the cylinder and piston. Never use a machine with 
a muffler that is in poor condition.
Needle bearing lubrication
The clutch drum is fitted with one of the following drive 
sprockets:
• A   Spur sprocket (the chain sprocket is welded on the 
drum)
• B   Rim sprocket (replaceable)
Both versions have a needle bearing on the drive shaft, which 
has to be greased regularly (once a week).
CAUTION! Use a high-quality bearing grease or engine oil.
Adjustment of the oil pump
The oil pump is adjustable. Adjustments are made by turning 
the screw using a screwdriver or combination spanner. The 
machine is supplied from the factory set to 1 turn open. 
Turning the screw clockwise will reduce the oil flow and 
turning the screw anti-clockwise will increase the oil flow.
Recommended settings:
These recommendations apply to JONSERED chain oil, for 
other chain oils increase the oil flow by one step.
!
WARNING! The engine must not be running 
when making adjustments.
Bar -15": 1 turn from the closed position.
Bar 15" -18": 2 turns from the closed position.
Bar 18" -24": 3 turns from the closed position.
Bar 24" -: 4 turns from the closed position.