On Tuesday, July 2, 2019 at 1:18:56 PM UTC-4, Chalo wrote:
The only Japanese square taper cranks I have come across that used ISO tapers have been branded Sugino. (I'm aware that Suntour cranks were at least sometimes manufactured by Sugino. But I don't recall ever having encountered ISO taper Suntour cranks.)

Sugino were ahead of their time in the proliferating-standards game when they introduced an incompatible proprietary square taper for their "Maxy" cranks.

I don't know which one this Suntour Cyclone crank has but when I slid the right hand crank onto a Shimano BB-UN51 cartridge bottom bracket there is about 1/4" left on the spindle flat and 1/2" between the crank and the bottom bracket cup. That is before tightening the crank fixing bolt.

Cheers