Bru
Not sure about that 20 oz amount. To the best of my knowledge that is the amount for the tranny and the primary still takes 32 oz. The original manual for the 05 had it listed at 40 oz, but myself and my dealer have been putting in 32 oz as per the change back in 05. By chance did you get the 20 oz for the tranny mixed up with the primary and if not where did you get the 20 oz from?
Sparker4Life
Would recommend that after you drain the primary, that you pull the cover as mentioned above and then clean out the cover and componets real well, inspect the clutch and all the other componets that you can see including making sure the tranny nut is torque, adjust the primary chain (do not get too tight) and then either with a gasket and sealer or o-ring, reinstall the primary cover and torque to specs with alternating pattern in steps, then fill through the inspection cover to proper amount, install inspection cover to torque and go ride and enjoy.
Personal recommendation for primary is good ole RevTech, do not recommend synthetic for primary and if you do, make sure it is for wet clutches.