Ok, long(ish) term update, it's a great overall ride. Once together it started and stopped just fine, until it didn't.
I'm riding along one day and doesn't the damn thing foul a plug, damn.... I get it home, pull the plugs, (no small feat either) number 3 is the culprit, but all of them look black as night. I knew it was a little rich (k&n stage 1 kit) but not that much. Anyways, I buy another set of plugs, pull the tank, airbox and carbs so I can reset the mixture screws from 3.5 out back to 3 turns. This is not what k&n suggests, it suggests lowering the needles first then the mixture setting, but I'm not that invested in pulling the rack apart yet. New plugs in leaner mixture set and we're off, it helps but again it returns about week later, yet now I've got an off idle and a below 4k stumble that I now know is a rich condition, above 4k it goes great. So now, I reset the needles. And at first again it goes like it should, until it doesn't.
So outta frustration I decide to set it all back to stock, I needed a baseline to start from. The original rack that came with the bike was essentially useless as all the slides were hopelessly stuck, but the bottom end components, floats, needles and seats and brass were pretty good. So here we go again, pulling the carburetors (3rd time) as well as pulling apart the entire rack to reset to stock configurations.
First thing I had a really hard time figuring out was float heights, the books goes by a clear tube reading, which is fine but its nice to have a hard float height to use as a reference. I can't find anything except for what Factory Pro uses in its jet kit (15mm) but that's with 122.5 mains, so when I measured the floats upon disassembly they were at 8mm, big difference either way. I reset to 10mm figuring if I'm going make changes, it'll be incrementally, one thing at a time. With that out of the way it's time to change out the 112 mains back to stock 105's for 1&4, 102's for 2&3, then back to stock needles and springs and mixture screws to 2.5 out. Reinstalled everything started and did a quick re sync and we're off, again.
Now it runs more normal(ish), ya gotta choke it now to start it when cold, before I didn't need to use the choke at all (a sign it was rich) I rode it this way for a week, plugs finally starting to look normal. Ok, so its time to start making changes one at a time, I replaced the stock needles and springs with the k&n's 1st, left the mains stock. Only real change I felt was and its minor, is its got a little more giddy up down low, but it's not fouling plugs, so we're good. So again, I rode it this way for several rides looking to see if it would stay or go south, it stayed, so we're good to move on.
Next change was larger mains, rather than install the 112's I decided to go with the 108's and see what that brings, if it works we'll go from there. Well, it runs so damned well with the 108's that I've left it that way. I can change to 112 mains w/o pulling the rack so if I choose to do so, I won't need to pull the entire rack. She starts at the touch of the starter every time, you can drag it down to 2k in every gear and twist the throttle and off she goes. I clear tubed the floats and we're good there as well. In hindsight I'm reasonably sure the real culprit was the float height, and if I decide to install the 112's I'm pretty sure it'll run fine. Sounds like a good time to sell.