Originally Posted by silverbear
You and I both tried the opti 2 on older engines. Mine was a dax with over a thousand miles on it and it improved in smoothness and power in just a couple of miles. I love it as the old motor has never run better. Why the difference in our experiences... yours worse and mine better? One obvious difference is that I had been using a synthetic since day one, Amsoil Sabre Professional. So maybe yours broke in differently than mine (or as someone suggested about synthetics, they never really break in at least in the traditional sense). I don't know, but if someone has been using a synthetic I doubt there will be any adverse effect from running opti 2 in an older engine. Just a guess. I am sold on the opti-2, quite a lot better than amsoil in my experience. I'm glad it worked out for you with the other two motors.
You might be on to something here. I've used the Stihl oil almost exclusively prior to the Opti-2. The Stihl is, and don't quote me here, a semi-synthetic. It is supposed to be mixed @50:1 but I've always used it @32:1 instead. Maybe you're right. There is a difference in how these two engines, yours and mine, were broken in. I'm going to research the Stihl oil today if I get some time and see what it really is.
The plot thickens.
Took a look at Stihl's website today and discovered that they have 3 types of 2 stroke oil. What I've been using, in the orange container is non-synthetic. The next level up is a semi-syn, and then they offer a full synthetic. Just thought I'd toss that in. STIHL Incorporated USA -- Products -- Oil and Lubricants -- Manufacturing the World's Number One Selling Brand of Chain Saws