Sorry I missed reading this thread until this moment.
I have an old Stewart Warner mechanical tachometer--the contact-the-shaft variety.
It needs a new rubber friction tip.
What if I run the Unite off a twelve volt battery and try for an rpm reading at the Unite's output shaft?
Would that be a help?
The motor is off of the bike at present, so if the tachometer works
this'll be an easy thing to do.
edit: ach! the Stewart is in perfect condition in its Canco tin can containment.
Since I last used it years ago the pot metal gear housing has apparently grown, and seized the internals.
I can perhaps do a physical count of the rpm at 6 or 12V, and you can extrapolate from there.
Mathurin wrote:...Something like actual no-load rpm would be nice.