Pretty much as the title say, I just picked up my 2013 GTR1400 and when taking the MRs on the back today, I decided to adjust the preload for the first time. I opened it out fully and could only tighten it 7 click from fully soft to fully hard. The ride was fine and suited the weight a 6 click in but in the manual it says there should be 12 no?
The pre-load adjusters have a habit of becoming seized/tight, this could be the situation you are experiencing.....try squirting some WD 40 or similar into the adjuster to soak and then gently work the adjuster in and out