After reading the procedure in The bird site, tech tips 700, and Haynes a million times and many many posts here i have finally realized that my fan only has one factory mark, actually a red notch on the back, rear of the fan - the 7.5 BTDC mark and NO TDC marks. I should have been using this but assumed it was TDC and was trying to set the timing to a point 1/2 inch to the left of it, essentially resulting in
A timing of 15BTDC. Lesson learned? keep trying and listen to the gurus on this site - they are terrific.