Bull,

I had 2 25GT engines from brillelli and they where great engines until I sold them to a club member so i could buy the Brillelli 40GT. I use Opti-2 two cycle oil in all of my 2 cycle gas engines. It comes in a 1.8oz package and all you do is poor that into 1 gallon of gas and your done. It works on all 2 cycles engine no matter the mix ratio. It comes out to a 70 to 1 ratio and I have never had a engine failure using it. When I first started using the Opti-2 two cycle oil I noticed an increase in 400 RPM on my converted Ryobi I had at the time. That Ryobi is still flying today in a club members 110" Cub. This is great oil. Here is the web site for more information about it. I get it at my local small engine shop who swears but the stuff.

http://www.opti2-4.com/