Re: 100:1 Mix
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.
Someday when I grow up I will probably lose interest in toys with wheels, but until then...