High 50's in my CB350 Four. Which was much like this one:
http://www.realclassic.co.uk/honda05012100.html
Except I got mine for $150. Replaced battery, contacts, and started riding. Within a few blocks the muffler fell off
, and Honda wanted $450 for a set of those fancy quad pipes. I opted instead for the $20 yeah-theres-baffles-in-their-officer straight pipe.
Rode it like I was trying to earn WDC points
and would get low 40's, which is what I'm shooting for driving like a pawpaw.
Note that this was a 400#+ bike. I can't find specs right now, but the p/w was pretty low.
I think I need to get another bike now D: