This may be of use to some...
Parking brake on my 500 which is cable operated from the drive select lever
(Some have separate handlebar lever) Just wasn't holding.
Simple adjustment is on the parking brake lever accessed from the RHR wheel arch...Brake operates on the rear brake disc & is in addition to the hydraulic foot/LH handlebar system. With select lever out of the park position adjustment is simply a nut on the end of threaded spindle on operating cable. If needed nut takes a 14mm spanner (wrench) but I found nut to be free enough to just hold threaded spindle with left hand - Need to hold return spring up off spindle & turn nut with right hand. You end up wrapped around the tyre & thin arms would help...Fiddly but quite doable.
The nut itself has an upper collar which is scalloped, which means that when tension is re applied to the cable, the scalloped shape matches the round profile of brake hinge pin (Hope that makes sense?) This prevents rotation of the nut & removes the need for a separate lock nut.
Adjust as required...I adjusted until it was hard to put lever in park position, then backed the nut off one full turn. On inside of return spring there is a rubber sleeve, this will need to be pulled back over threaded cable adjustment spindle on completion to prevent corrosion of spindle thread.
Finally test run bike, feel rear brake disc on return to make sure no excessive heat due to binding & test brake hold on incline...Not very steep though! Sorry if this seems "Long winded" for such a simple fix & hope I have not insulted anyone's intelligence in the process.
Photo attached which may help, but not too good with wheel in place.
John