Get a decent 2-stroke synthetic oil and mix it according to the bottle. It's the oil that determines the mix ratio (for the most part). Stihl oil that I use I mix at 50:1. At this ratio, there is very little smoke, and I never have fouled spark plugs. Also, as a 'bonus', you can use it in ALL you petrol powered machinery with no ill effects. Saves making an expensive mistake, as you only have one fuel can on site.
Phil Saunders, November 2012
