From the larger pic, it looks like the bellcrank for the cable attachment is spaced out on the throttleshaft, but it's hard to say. If it's not, it can bind on the choke rod you can see right at the front of the bellcrank, where the barrel on the end of the throttle cable attaches.
Speaking of that barrel end, it looks abit askew to me, so maybe it is binding against the choke rod. Look that area over real good.
It is spaced out with a washer off the hitachi, this was to rule out binding on the choke rod. All is clear there.
... I do not see this spring in your picture
Good observation, but the spring installed did not help.
To simulate your position I placed a spacer in the bore.
The thickness of this spacer is 0.010 "
Yes 10 thousands of an inch
I would say that is spot on.
I have the carb off, sitting on my kitchen table.
The maximum closing stroke leaves about a .010-ish" gap.
I would assume that the secondary throttle plate needs to close off the venturi(?) just as efficiently as the primary side does.
Am i correct in this reasoning?
If that's the case, i think i may have to file a very small amount off of the sides of the plate, because it is rubbing (i can see the mark).
Loosening the two screws and adjusting it doesn't seem to help close.
Geez, i didn't think i'd have to actually learn about the thing when i installed it.