I found that the standard throttle was that 2 turn handful that made things a bit difficult to get to full throttle quickly.
I was renovating a Honda XL250SA at the time and was wondering what to do about the 750 throttle.As I had the 250 in bits I tried the throttle tube and the cable holders with the 750 cables...and they all fiited.These parts were readily available from Honda at the time,and changed the opening time of the carbs from closed to fully open to a much shorter time.
It also did away with the right hand switchgear,which meant that other arrangements had to be made for the lights/horn/kill...but that is another story.