Kickstart RPM

Sorry not a norton twin , but i think when you see the tach just giggle at the bottom it must be about 200rpm , My Bsa B33 has M20 flywheels and 94mm stroke and that's mated to a Harley evolution piston +.030 nearly 90mm bore, so just under 600cc single .I've just reduced cranking compression from the shovelhead piston it had , I still have 170psi and the motor had been running that day but the cylinder was fairly cold , I've done up the magneto and changed it to slack wire full advance , it has big valves 45mm ex and 47mm intake , with a phf 36mm delortto pumper , I got it dialed in pretty good with AFR gauge , cold starting is good , use only a little advance, full choke and two pump shots and usually it's going in 1 or 2 . Starts ok hot but I need to get used to what it needs , but it can kick back , really badly ! I find it's best to not have my leg fully extended and if it kicks back I stay loose and don't fight it .

The doctor let me take off my straight jacket so I can do some writing therapy.

This start RPM thing seems a little overthunk to me. I'd set the magic advance switch on the future magneto at 400 RPM. I doubt a Norton twin would run well enough for the ignition curve to be that important below or at 400 RPM. If that did not work, and the object was to use more ignition advance to improve idle, I'd try 250 RPM. Another option would be to include a potentiometer or dip switch to let the user set the advance start.

These work well. Will give a starter motor rpm. Handy when timing the bike single handed ,I.e , adjusting idle to 3000 rpm. It also appears they work on outboard and Harley's!!