Boy, what a bunch of manual Tweekers!
On any plane that isn't weight critical I use a specialist servo driven remote mixer needle assembly.
I've 'em for both OS and Moki engines and there are several available from after-market specialists, BMV for example.
You basically set 'em up manually and then do the final tweeking (loads and loads of available adjustment) via a dial on the tranny!
Where have you guys been? The jet boys have used these for years, they work GREAT!
I had one in a CG Extra (shows how long ago the was) and I never touched the needle in several years.
Im surprized that you scalies just haven't got light of this. How many competition flights where you intending scratching because your engine went lean/rich 2 mins after take off?
Turn the knob on your tranny, fix the problem and save the round.