40:1 = Standard Synthetic 2 Cycle Oil, post breakin.
32:1 = Standard 2 Cycle Oil, post breakin.
24:1 = Standard 2 Cycle Oil, pre breakin.
You'll blow a ring, or your rings won't seat right and you'll never have good compression if you don't follow this. You can score your cylinder wall, sieze the motor, blow bearings, etc etc etc.
Has to do with the richness of Fuelmix to air/air to fuelmix, fuel to oil/oil to fuel, fuelmix to sparkheat, sparkheat and fuelmix to displacement etc etc...
There's too many variables to tell you this late at night, so I'll just say, learn every single square millimeter of your 2 cycle first, and then after that KNOW that every component is a variable, whether it seems like it or not. Once you learn what interacts with what and how, you'll be set to learn about tuning it from top to bottom, tip to end.