RE: OS 46FX Midrange Lag
QS Pilot,
The engine's behavior and response to opening the throttle in a hover, can only be determined and adjusted, with the model in hovering attitude...
If you adjust the transition quality perfectly (the low-speed needle) with the model on its wheels, in level attitude, it will be too-lean, with the model in the full nose-up attitude...
What you are seeing (the engine 'stumbles' momentarily) suggests too lean a setting, rather than a rich one.
If it was too rich 'nose-up', it would load-up and sputter when the throttle is advanced... Even more so with the plane in level attitude.
Sorry to have to contradict you, Jim.
Also, to get a perfect '1/3 to full' transition; adjusting for a perfect 'idle to full', or 'idle to half', will just not do the trick...
It must be done in the target attitude AND in the target throttle range.
Also, regarding your fuel; 'Cruel Power' all-synthetic is not the right fuel for this engine.
If you want it to run right and to last, you must use fuel that contains a reasonable amount of castor oil.