Hi all , I would like to know if the problem I am having is fuel foaming or something different. I have normally used Cool Power 15% fuel in all the engines I ran up untill 2 weeks ago without any problem in my engines. I switched to Wildcat 15% with 80/20 oil mix. My problem started when I tried to fly my giles 202 with a used ST 90 with new carb on it. The ST would run for approximately 3 minutes and then start bogging and eventually stop. I discovered it was extremely hot and assumed it didnt have enough cowling removed. I then ran the engine on the the ground with the cowl removed but ended with the same results. I replaced the tank and lines and made sure of no air leaks (water tested in sink) and checked for carb leaks. After 3 unsuccesfull attempts at getting the engine to run cool I extra wrapped the tank with foam. This did not help the situation it still heated up and quit. I am running the engine to the max fuel rich setting. I got tired of fiddling with the engine so I installed a NEW ST 90 ......same problem with the new engine. In the proccess of trying to figure out my problem I was also helping my girlfriends son finish up a airplane with a NEW GMS 32 engine on it. We took it to the backyard and was attempting to break it in when it had the same affect that the two ST90's (heated up and quit). It seems that the vibration from the engines had some foam inside the tank on his airplane but I could not see the tank on the giles so I was not sure if this fuel foamed on the giles also. My question is does this fuel foam easier than the cool power and if so why can I fly two other airplanes (t-34 and patriot jet) without any problems? All tanks are foam covered and fit tight within the fuse. I am goign to purchase a gallon of cool power and run that again this weekend coming up. I purchased the wildcat thinking the 80/20 mix would be better than a 100% synthetic mix. Thanks