Okay, I just checked tonight. This is what I've been running on two (consecutive) 1st Gen B12's :
Mains: 117 (stock)
Pilots: 37.5 (stock)
Needles: second clip down from top.No spacer.
fuel screws: yes, FOUR and a quarter turns out.
I have the famous 20 holes drilled in back of the airbox, and have removed the rubber snorkel. On the exhaust side it's a stock header with a Yosh RS3 end can.
I've been running it this way for a long time... (two bikes, probably 20,000 miles). It seems crisp, but just lately I've been gettting some instability just off idle. I pulled one plug the other day and it looked a little whitish in the center.. nothing extreme,.. but I may be tinkering again soon.
But otherwise, the bike pulls cleanly right up from idle to redline without a flat spot. I imagine I'm not doing it BEST.. and with more F'ing around could improve it. I'm thinking about larger mains... but I seem to recall DOING all this four years ago, and settled on what I've got now.
Anyone wants to try this weird set-up, I'm really curious to see what they find. So far it's worked for me.