TIMING DEGREE WHEEL

I want to set the timing on the Norton accurately. I've been searching for a timing degree wheel to buy or print off a pdf. The only ones i've found are 360 deg but heard that a 720 degree one is needed. Does someone have a .pdf or can point in the right direction?

Try this: http://www.mapenterprises.net/mapcycle/map_0850.htm
you can also go to Top shelf Parts on evil bay same people.

Thanks thats exactly what i'm looking for.