FUEL HANDLING
18 – English
Fuel
Note! The machine is equipped with a two-stroke engine 
and must always be run using a mixture of gasoline and 
two-stroke oil. It is important to accurately measure the 
amount of oil to be mixed to ensure that the correct 
mixture is obtained. When mixing small amounts of fuel, 
even small inaccuracies can drastically affect the ratio of 
the mixture.
Gasoline
• Use good quality unleaded gasoline.
• CAUTION!  Engines equipped with catalytic 
converters must be run on unleaded fuel 
mixtures. Leaded gasoline will destroy the catalytic 
converter and it will no longer serve its purpose. The 
green fuel cap on saws fitted with catalytic converters 
means that only unleaded gasoline can be used.
• The lowest recommended octane grade is 87 
((RON+MON)/2). If you run the engine on a lower 
octane grade than 87 so-called knocking can occur. 
This gives rise to a high engine temperature and 
increased bearing load, which can result in serious 
engine damage.
• When working with continuous high revs (e.g. limbing) 
a higher octane is recommended.
Environment fuel
JONSERED recommends the use of alkylate fuel or 
environmental fuel for four-stroke engines blended with 
two-stroke oil as set out below.
Running-in
Avoid running at a too high speed for extended periods 
during the first 10 hours.
Two-stroke oil
• For best results and performance use JONSERED 
two-stroke engine oil, which is specially formulated for 
our air-cooled two stroke-engines.
• Never use two-stroke oil intended for water-cooled 
engines, sometimes referred to as outboard oil (rated 
TCW).
• Never use oil intended for four-stroke engines.
Mixing ratio
1:50 (2%) for all engines.
Mixing
• Always mix the gasoline and oil in a clean container 
intended for fuel.
• Always start by filling half the amount of the gasoline 
to be used. Then add the entire amount of oil. Mix 
(shake) the fuel mixture. Add the remaining amount of 
gasoline.
• Mix (shake) the fuel mixture thoroughly before filling 
the machine’s fuel tank.
• Do not mix more than one month’s supply of fuel at a 
time.
• If the machine is not used for some time the fuel tank 
should be emptied and cleaned.
Chain oil
• We recommend the use of special oil (chain oil) with 
good adhesion characteristics.
• Never use waste oil. This results in damage to the oil 
pump, the bar and the chain.
• It is important to use oil of the right grade (suitable 
viscosity range) to suit the air temperature.
• In temperatures below 32°F (0°C) some oils become 
too viscous. This can overload the oil pump and result 
in damage to the oil pump components.
• Contact your service agent when choosing chain oil.
!
WARNING! Always ensure there is 
adequate ventilation when handling fuel.
Gasoline, litre Two-stroke oil, litre
2% (1:50)
5 0,10
10 0,20
15 0,30
20 0,40
US gallon US fl. oz.
1 2 1/2
2 1/2 6 1/2
5 12 7/8