Preload = 1, 2, 3, 4, 5 (always turn the adjuster CW) depends on your weight and SAG setting.
Rebound = 1, 2, 3, 4 Usually the setting is 2 or 3. I test it on speed bumps to see when the rear end stops jumping.
Forks = the Gen2 (41mm) forks are much better than the Gen1 (38mm). I don't like using heavier weight fork oil to compensate for a poor fork design. The simple is to install Progressive fork springs with spacer, use ATF.
My used A19 came with the Progressive springs. I added longer spacers, changed the fork oil (ATF) level to 170mm below the top of the fork. Then I was given Ricor Intiminator fork valves with Amsoil synthetic 5w. This made a big difference and calmed the forks down to a performance level. Later I installed MotoWizard Preload Adjusters and removed the spacers. Makes it easy to fine tune your forks without removing the fork caps.
2005 KLR 685
2015 Yamaha Super Tenere ES, 5/23/2015
2012 Yamaha Super Tenere; Purchased 7/30/2011; Sold 5/23/2015