I was going to upload a video of my BX23S sputtering throttling down and up without me touching any controls at all, but it seems I can't do that here. (If anyone knows how I can, please let me know.) I've had a knowledgeable repairman help me but still, I get about 5 minutes of run time before the engine dies. Can anyone help me figure out how to fix this problem? I could post the video somewhere else maybe - if that doesn't violate the policies of this site......?