All hire companies use 25:1 mix with a good quality two stroke oil. ie:20mls per 500mls petrol or 40mls per litre. Anything less can result in seizing as modern saws are revving to 10-12000 rpm. Hope this helps.
Geoff
May 2009
Normally you would mix 100ml oil to 5 litres petrol for a 50:1 mix, but if you only want to mix 1 litre, that would be 20ml oil.
John
May 2009
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