When I go full-throttle, it bogs down and dies on me... and when I drop it down to below full, it kicks back in. So, I'd assume that this is a jetting problem... also, a small engine repair-guy told me that if the things that were happening happened, I should check my jetting.
Also, I guessed that it was a screw thing, and so I tried to unscrew it, but it wasn't budging... I think the stupid thing's too dirty right now... so I'm going to soak it for a couple days in some cleaner, then try again... hopefully, it'll be a little more forgiving next time around. Thanks for the help!