Need to know fuel mix for mcCulloch gladiator 550 petrol hedge trimmer

I don't know the age of this machine, but more and more of the newer units are using a 50:1 mix to satisfy the newest EPA emissions regulations. I suggest using a synthetic or synthetic blend of 2 stroke oil. ....the big box stores sell the oil...Echo one of the best. I would use synthetic and mix it 40:1. Here is a fuel mix chart to show you how many ounces of oil in a gallon of gas that is. If you make a 1/2 gallon batch of fuel mix, just use half of the listed oil amount for the mix.

http://support.mtdproducts.com/app/answers/detail/a_id/347/~/two-cycle-engine-fuel%3Aoil-mixture-chart

40:1 is 3.2 ounces of oil in a gallon of gas...or 1.6 ounces of oil in a half-gallon of gas