I guess it could have hurt something being that lean, have you done a compression check? or a leakdown? If that goes well then,
I think I'd jet it down and make a run, jet it down make a run ect..Until it quits picking up, Then do the timing same way. Must be way fat, or something going wrong with a bearing or something...
When was the first run made and the last? Don't forget to figure in the weather it usually slows me around a tenth-a tenth and a half.