I just went back and reread Bill's original post. I didn't realize YS was going to start selling this retrofit. I thought it was a one-off, which is the reason I mentioned trying CH Ignitions. Sorry for the confusion!

Bill, do you know anthing about the timing curve of the EI system? I assume it has retarded timing at lower rpm, advancing as the revs increase. My big gas planes are wonderful to start and won't backfire because the plug won't fire until the piston is travelling downward (I think it fires at 2* after TDC, and advances to 28* BTDC after about 4000 rpm).

The 600 rpm idle and low fuel consumption sounds phenominal!