Hello all,
New to the forum. Hoping to learn what I can about the Tillotson HD series carbs here. I am a bigtwin owner. The technical section and service bulletins are great. I've studied the HD fuel flow and cross section diagrams such as in SB 518, and have a question I hope someone can answer. As I clean a stripped body of an HD2D with carb spray, I noticed a small opening in the bore I had not seen before. At first I thought it to be a casting flaw, but then found the same opening in multiple bodies. Looking into the bore from the choke end, the opening is in the floor of the bore, to the right of the small boost venturi. The cross section diagram does not indicate an opening here.
The only answer I can come up with is that the cross section diagram is wrong in identifying the location of the "Idle Air Bleed" channel.
Has anyone else noticed this?