finally got the lambda sensor hooked up and went for a spin today. 912 UL with base settings, except needle in richest position. Measured AFRs, sonde on outlet so measures both banks together
- between 12.5/13 when taxiing so idle circuit is good
- 2000-4000 same, on decent/no load around 13-14
- 4000 and up on cruise it leans out and at 4800 I have AFR15
- 4800-5300 straight and level 15.5, which explains the less than perfect running. Pull out choke and get 14.5 and clean running
- full throttle , including full throttle climb, I see 12.5-13 to it seems main jet is OK too

So I think I need a larger needle jet. I have a 2.72s

New ignition leads, caps and modules
individual KN air filter pods
All carb parts replaced
Perfect leakdown numbers on all four
220 hrs total on engine

Any advice, or comments would be welcome