RE: SIG Aviastar .46
After three days of experimenting and with some help from littlecrankshaft I have happened on a combination that gives a decent idle.
67 degree day
90% humidity
5% Nitro Ritchs Brew
APC 11 x 6 prop
McCoy 4 stroke plug
11,300 RPM high end with a 2700 RPM idle. Idle is reasonably reliable but not very reliable below 2700 RPM. Further running may improve performance. The low end is still pretty rich and I am not able to lean it further at this time, the 4 stroke plug keeps it running.