I picked up a 3000 ST and am not sure what mix of fuel to use. I have tried a 15 / 18 and it runs good on the ground. Get in the air and after running full throttle for a short time it dies. Then a recovery mode is nessary. Is it the prop size? Is it the fuel? Is it the file tubing? Is there a connector and clunk bigger to make it run good. Don't know which way to go. If special fuel is needed where do I get it. Now that is a lot of questions isn't it.