According to my Owner's Manual, the numbers go from left to right, so turning the adjustment CCW, looking down from the top, should decrease it to 1; that would be rotating the left shock towards the back, the right towards the front. It should stop at 1 and not go any farther. If they are like other Honda shocks, turning past 5 will cause it to jump back down to 1, which isn't really a good idea; don't know, as I have the Goldwing air suspension, installed by the previous owner.
Check out p.17 in this:
http://www.hondampe.com.au/docs/owning_a_honda/owners_manuals/motorcycles/GL1500C-1997.pdfIt's the same for the '98.
Hope this helps.
Rick