I'm pretty new to this and don't know that much about the fuel mixes yet, but according to thatsdax i found out that i should just keep my mix at the same 20:1 ratio after break in. i also found the above addy very helpfull for measuring different mixes. hope that helps ya some.
if you have a 2 stroke engine, i think any 2 stroke oil will work. you should probably find out what the manufacturer of your engine recommends to be sure of the gas/oil mix ratio. in my manual from thatsdax it said to mix mine at 25:1 during break in. on his website it said 20:1 for break in and after break in. I have read thru other posts in here tho that said some people use different mixes, i have no idea why to be honest. some of these other guys no A LOT more about this stuff than me. I'm just a beginner. lol
After break in (actually a couple hundred miles should be more than sufficient) you can run at 40/1.
Any good name brand two stroke oil for AIR COOLED ENGINES is good.
Don't use the stuff for outbaord motors.
Synthetic you can run at 50/1 after break in.
Running too much oil in a two stroke is as bad as too little, but for different reasons. You WILL make a massive carbon build up, which will ruin plugs first, but eventually it will clog the exhaust, make the ring(s) stick (really bad) and more.