(I may be the only one who cares about this engine anymore, but I'll give it one more whirl, may be a general engine issue this folks can help with.)

I may be having same old issue of too rich LSN and too wide idle gap, however I have tried avoiding it, got the gap quite small. But I still get what I believe is referred to "runaway", or high idle that does not want to settle. Not on the bench, but after laps.

What happens for me is I tune the engine warmed up on the bench (140-220 degrees) but after running some high speed laps on the track my engine likes to take off on its own after I let off the throttle, and then when I bring it in it doesnt go back down to idle and I have to kill it. I assured the carb is closing properly (spring). I have a few more things to do verify air leaks/proper seals tho. Is it possible that as the engine gets real hot air leaks present themselves? I had to zip tie fuel lines because as they got hot they lost seal. I wonder if air is getting into the engine somewhere.