LOL
Oil ratio and jetting aren't interchangeable.
Oil ratio is also not responsible for fouled plugs, that falls on improper jetting.
If you're getting a leak in the case it's either from bad crank seals or a **** case.
If you can actually FEEL the air leak, you've got a serious problem (unless you're feeling air being moved by the flywheel).
Time for a leak down test and visual inspection...