Mike, your lean condition seems to be similar as my bike had before but opposite. I had too rich where you have too lean.
http://forums.sohc4.net/index.php/topic,147350.msg1677539.html#msg1677539It really bogged down at WOT, cleared out around 6500 rpm with 4-1. Comments about needles were correct which was verified later on another dyno with 4-4 2 years later.
In the first scenario I changed cam and the problem disappeared without changing the carb jetting (TMR32). The Megacycle cam was more sensitive with too rich needles. Action Fours SS-1, RC295 profile and DP315, all ran OK at WOT with same needle settings. Another thing when cruising on low lifts from 2000-5500 rpm. A/F ratio was around 11. See attached pic. These thin blue a/f lines cruising 2000-5500 with too rich needles (that bogged down completely with Megacycle 125-20 and 836cc earlier)
I changed needles 2 steps leaner (1 step each time + road tests) and next dyno showed correct values this was with 4-4. I tested the same Megacycle cam earlier this year and it did not bog down as before when needles were OK.It did not rev out with 4-4 though.
Now 4-2-1 and it runs better than ever (RC295 profile). Needles feels OK too. Only fuel screws that are not perfected and main jets not verified on Dyno yet (or full speed on a remote road). (Water drops in carbs after cleaning the bike had messed up the fuel screw adjustments which took a while to get verified. Carbs had to be blown free since water did not want to leave.)
You might try to lift the needles 1 step and try the same cam once more.
Edit: I had a fuel screw road test today with small adjustments.
I guess that adjusting needles on RS34 is as easy as the TMR32 without affecting synch.