Agree Nev, no need to be shy, even if they are "old clangers" I have never heard of a petrol engine that cannot be better with an adjustable advance curve and I would not be calling the technology breakthrough fancy either, they worked out decades ago that there is a measurable advantage.
Just because back in the day, and now, they can operate on full advance once underway, it defies basic combustion engine principles that an improvement cannot be had with different timing for changing loads and RPM. I know your thumb can do this for you on an 80 year old system so I do not understand why the "new BTH" cannot do it for the price these days.
If your a putt putt putt rider, standard is fine, but if you twist the wrist a bit, an advance curve is a definite advantage and compliments all the other performance parts you have fitted like cams, head work, exhausts and higher comp pistons.
I would like a system such as the similarly priced older Harley replacement ignition systems have a switch giving you have a selection of advance curves so as you fit parts you have a choice of curve. Gees, I even remember changing springs in Dizzys to alter the advance curve decades ago, looking back they seem high technology to a unit made in 2013 with no way to alter an ignition curve.
"The units push out about 25kv by the way well up with the originals" does not instill much excitement either, as a potential buyer I would of hoped you would have a unit these days that was definitely equal or better than a 80 odd year old designed unit, sounds like it is only close to the originals.
Can you tell us if there is any design improvement/development you are currently working on for these replacements ? I am not knocking your work or quality Tony as it does look very good but there is potential for a more advanced unit for those of us who may be looking for a performance replacement and do not already have a genuine BTH.
I still do not know the answer to my question either. Anybody ?