Hi everyone. I have a ryobi 31 cc that runs strong for about 12 or so minutes. It starts easy and transitions very smoothly with plenty of power. Here.s the problem: after about 12 or so minutes of running, it will falter like it is runing out of fuel for a few minutes then die. I have had to dead stick this thing a few times and you can tell when it is getting ready to die due to the faltering. Once it dies, I can't get it started again until it cools. If you try to start it when it is still warm, you can see that there is air in the fuel line and the carb will not pull the fuel back to the carb unless you fully choke it. Sometimes you can get it to run fully choked but there is no power obviously and as soon as you try to throttle up or open the choke it will die. I can either let it cool down or wait till the next day and it will start the whole scenario over again. It acts like it is letting air back through the carb. once the engine gets warm. Also, it didn't use to do this. I have flown around 4 or 5 hours of actual flying time before it started behaving this way. There are no holes or air leaks coming grom the tank on to the carb. Any help would GREATLY be appreciated. Thanks, Todd