Could you tell me what you mean when you say you had the same stumble? Mine is only at 0%-5% throttle. Thats it, other than that it runs flawlessly. It is definitly throttle position related, as RPM has nothing to do with it. Please let me know if you've solved something similar. I'm getting ready to take two hours to a pro if I can't figure it out. Thanks again for the help. -Eric