Re: 100:1 Mix
Given the length of this thread, I never would have imagined I had something to add that has not already been said. That is, until I stopped by a Tractor Supply Co. store today...
For everyone saying they cannot find Opti2 locally, TSC may be another option. In their mower / chainsaw / trimmer section they had little packets of 2-cycle oil that looked suspiciously like the 1.8oz opti packs. The label says "Arnold" brand universal 2-cycle lubricant, but the instructions are the same as opti (that is 1.8 oz pack into 1 gal). Also the back of the label says "manufactured for Arnold by Interlube International Inc." the makers of Opti.
Sounds like the same stuff to me.