hpp set up thread (86/87) specificlly

just wondered if theres a detailed thread on setting up the powervalves on here. ive come across a pdf from the manual and also eric gorrs' tech tips but im still not having the best of luck getting mine perfect. im after tips and things that may assist that people have found makes the job easier. my issue is using a 89 case. the l/hand valve seems to hang open a touch unless i preload the spring by way of a milled gown m6 bolt that screws into the the bung. i suspect that the valves maybe off a touch but ive tried adjusting lia the box end/eccentric adjuster to no avail. they do close fully with added preload so im guessing they are actuating fully through there range. they also open fully when the bike is blipped at around 6k. should i just run with the added preload or should i see if i can adjust perfectly? thanks in advance