Re: 89 gas
Octane has to do with fuel ignition under compression. High compression engines require high octane fuel, so that the fuel doesn't ignite in the cylinder before the spark hits. Low compression engines don't benefit from a higher octane fuel. Unless you've done some crazy head milling or added a Puch head or something like that, I highly doubt these little motors have enough compression to warrant using high octane fuel. Same goes for cars. If you don't get spark knock on 87 octane, you're not going to get more power out of 89 or 91 or 93.
Some fuel suppliers talk about the different additives in the different grades of fuel, and maybe that might matter over the longer term in a four-stroke engine. No fuel supplier I know of, though, takes special measures to formulate their fuel to run well in a two-cycle. Your two cycle is going to get carbon buildup all over the piston and ports and exhaust from the oil, not from the fuel, and there's not enough additives in the world to make a difference in that.
If you're going to spend money on fuel, spend it on the oil and the fuel filter. Get Opti-2, so that you can run less oil in your mix. More gasoline in the mix means more explosive power in the cylinder. Use a good metal core inline filter, and change it from time to time. Clean your carburetor once in a while.
If you're going to be picky about the gasoline you use, be picky about the station you buy it from. Sometimes it's hard to tell, but overall, you're going to get better gas from a clean, nationally branded chain station than from a dumpy, mom and pop place. Gas stations that don't take care of their convenience store sure aren't going to replace their underground tanks until there's a foot of water in the bottom of them, and in the meantime, you're going to be pumping a little bit of groundwater and dirt into your tank.