Well, I took HC#42's suggestion this afternoon. I took the carb apart again to clean it, and possibly swap out the main jet. I hadn't taken out the pilot yet, so I thought I would, to see if it needed to be blown out. To my surprise, it was a 52. I went back and looked at all the jetting charts I have saved, and almost none of them call for a 52.
The bike has always felt fine in the low end, and it idles fairly well. I decided to throw in a 55 pilot, and give it a shot anyways.
WOW! The change in low and mid power was substantial. The bike did not want to keep the front tire on the ground. We went to one of the same hills we have been trying for the last month, and I made it another 50 yards up it this time. This is a trail that goes up a mountain side, and just ends, because no one can make it any further.
It still isn't perfect, but I can tell I am on the right track. I think I might still try a larger main, and see what happens. The other thing I haven't touched is the air screw. I think that will put the final touches on the performance.
Thanks for all the suggestions.
Darin