After using synthetic oils I will never go back to Dyno oil. The new Solos are good to go at 50:1, I ran my old Mag 2000 for 3 years at 80:1, the current owner does the same and she runs like a dream. According to Nils I can run Amsoil up to 100:1 without issues, after break in at 50:1. So afr it runs like a champ, have 1 season on it and will get many many more.