Very good point there. I was telling people this about a month ago and didnt feel like starting it over. A very good testament to what you stated is that I used traxxas top fuel 20% for awhile because my lhs was out of the ODonnell. This is the stuff I use, the r2r 20% http://www2.towerhobbies.com/cgi-bin...?&I=LXMGF8&P=0 Anyway, the "top fuel" always caused my s-25s, savage and mt2, to run hot, around 280, and would often evaporate causing a lean mix. Then to get it to restart, I would have to set them very rich, and have to constantly retune the engines every other tank or so, until I ran into the evaporation again. To sum it up it was a nasty and annoying cycle. Kinda caused me to question my tuning ability. Finally switched back to the ODonnell, and the first time I retuned to adjust for the different fuel, ran about 7 tanks in a row without having to touch the carb again. Only quit due to lack of daylight, which is very satisfying compared to quiting due to frustration or overheating. By the way, switching back to good fuel, my temps never got over 240 in the big block. I know it wasn't some crazy coincidence that it turned out this way because I ran the remaining 2 tanks worth of top fuel I had and then switched fuel and retuned withing an hour of running. I would rather wait for the ODonnell to come back into stock before I go through all that again.