I have a Magnum .46 and it runs great, it has all the stats of the OS .46FX. I have never had it quit running. I have it on a KAOS. It will pull unlimited vertical until almost out of sight. I also have the Tower .46, this also has been a great engine once you open up the idel vent hole in the front of the carb. It idles real slow and steady now. And let me add one more motor that is cheap but runs strong and is very reliable, the Thunder Tiger .40 and .46.