Originally Posted by CharlieT
In a simplified explanation, the lower the rpm, the less oil is required in the premix. The higher the average rpm range run, the shorter is the contact period for the oil to be deposited and the need for more oil to be present in the mix.
Thanks, CharlieT, good information. I am a recreational rider, not a racer (just like to pretend). I will NOT be riding high rpm, all out MX. Most of my time is easy to moderate desert trail riding - no enduro racing. Looks like I have some room for experimentation with ratios, likely don't need to start with 20:1. I certainly have need for further education. I used to have a good 2-stroke tuning book - will look online, etc. for more info.