912UL CV carbs without airbox-what is the fix for the lean running ?

got it nailed now. After cutting back on the slide spring another 1/2 coil I now see AFR 14.5-14.9 at cruise. I have the 2.74 needle jet and needle in richest clip position and it transitions beautifully onto main jet when I load up engine at climb and apply throttle so it appears the slides operate as they should. Unlike before when I only got onto main circuit at full throttle climb. Now transition from cruise to WOT at climb is gradual as I start loading up the engine. It feels more powerful too between cruise settings and WOT.   2.76 needle jet is very muchon the large side for the 3000-4000 range and it runs rich here. However in the air it runs great at any throttle setting. The lean condition at cruise that had me worried about burning valves or worse is gone and engine runs smooth and happy.   I might try raising needle one notch later to see what happens in the 3000-4000 range or not, and/or try with 2.74 needle jet, but if I did not have AFR readout I would not be anything but very pleased with how it behaves now. As compared to how it was with stock settings.   Not suggesting anyone should use my settings, not without AFR meter anyway to closely monitor what happens. Engines don't always behave the same and according to Bing support a 2.76 needle jet is too large but I really could not find any other way to get enough fuel at cruise.   The other significant change was the cutting of the slide spring that helped a lot too.   Please note I don't recommend any of this to others except if you should have a slightly rough running 912UL then maybe it could be related to fuelling...

any issues seem to gone with the install of EFI. Runs smooth as silk at any throttle or load setting now.   LAD-Aero. Well thought out and quality ECU and other components. Easy install too. Took us two days to install and started on first attempt.   Have 15 hours on it now, in only 4 days and could not have been happier.  I purrs at 1500-1600 RPM, and at any RPM above and lambda values are perfect over the range after a short teamviewer session.   

EFI is a certain cure for the common carb :-)  Now if they'd only put some prices on their web page.  Hopefully it's not insanely expensive like the other aftermarket injection options.

Rusty