Need more info. You have checked the throttle body to ensure you don't have some kind of funky mix running in the radio, right? Throttle should be fully open at full throttle, etc etc.
At full throttle, does idle sound different than at idle setting? A little faster but very rough? You did break-in and have manual, and have read it carefully, right? All that stuff about how to set the high speed needle? Sorry to seem patronizing. Gotta ask. Does engine continue to run at full throttle or does it die after a few seconds? Sounds like it's running rich to me. Turn the high speed needle at full throttle and see if engine picks up speed when you sloooowwllly turn the needle in.

You could also do a search here on RCU, there was a post not too long ago which had some excellent setup advice in it.


Andy