Re: Regular with up to 10% booze-a-haul, or high octane w/out?
Since I've already done the ethanol experiment, I'll share my findings.
The majority of the parts in these kits work just fine with ethanol fuel. The only parts I have found that need replacing are the fuel line(any quality fuel line will do), the float bowl gasket on the NT carb(this thing melts with E85), and the stock petcock(which is a piece of chinee junk anyway and should be replaced). Other than that, I have run my engine hundreds of miles on E85 with no negative effects. The only downside is the amount of tweaking involved; you have to re-size the jet in the carb, and even then, it can be a little tough getting the engine to idle properly. Oh, and you can only use ester-based synthetic 2-stroke oil, which can usually be found at motorcycle/dirtbike shops.
Running on mostly ethanol shows a noticeable decrease in power, but marginally. It still hauls my fat rear up hills. If you are riding on a level grade, chances are you won't notice any significant difference in power.
I have also run my engine on pure denatured alcohol and it runs just as fine.
So is E10 gasoline bad for your engine? In my opinion, no. I am sure there are some other older 2-stroke engines that have issues with ethanol in fuel, but I have found very little evidence to show that ethanol is harmful to our little bike engines themselves. The only thing close to that would be the fact that ethanol absorbs a lot of water, and supposedly running old ethanol fuel in an engine will cause rust. But then all you'd have to do is keep ethanol in a sealed container and try to use fresh stuff as much as possible.
Sure, I don't see any harm in using pure gasoline, but with these engines, I doubt there will be any significant difference in engine life and performance. I personally prefer ethanol fuel because it is cheaper and it has an awesome smell to it. Riding with gasoline made me smell awful after a ride, but I don't have that problem with ethanol.
By the way, if any of you have seen my thread on my broken crankshaft, I am certain that was not caused by my ethanol fuel. I foolishly tried to hammer off my small bevel gear multiple times(and failed), and I think that jacked up my crankshaft.