Originally Posted by goball
30yearTech is probably correct "at least in theory" and is no doubt speaking from experience but I've been quite successful (or maybe lucky) in running every 2 cycle machine I have or have had on Optimal synthetic oil at a mixture they recommend of 100:1. Just got finished refurbing three grass trimmers that seem to work well on the Optimal. Your choice and depends on how much or how hard you plan to use the old Homelite. I have two old Homelites (a Super2 and XL2) that I use for cutting firewood at the cabin. They seem to be happy with the Optimal at 100:1 ratio. Good luck.
Way back when we first started selling Opti oil mix, there were literally several dozen chain saws that got trashed when the customers switched over to the 100:1 ratio oil, not from lack of lubrication mind you, but from the carbon that had built up in the engine. As the synthetic oil cleaned out the carbon, pieces of it would come loose and get between the cylinder and piston and cause severe scoring. I think the synthetic oils are fine, if you start with them and stay with them, it's the switching over that I am suspect of.