As the above two posts say,
long term solution is probably best to stiffen up the forks by mechanical means, if they aren't actually leaking air and oil at present, then the kind of small volume hand air pump used to set mountain bike suspension (schrader type valve fitting) or available from some of the better bike accessories suppliers (possibly MnP, Busters, Demon Tweeks, or suspension specialists like MH, KAIS, Pro Action) is the most effective way to accurately set the pressure, ordinary footpumps, compressors, bicycle pumps will tend to release air on disconnection, making accuracy difficult.
Air assisted or fully air only suspension can work, but needs a fair bit of maintenance and upkeep, once bushes and seals start to wear much, pressure will revert to atmospheric quite quickly and damping oil may also leak out, whereas mechanical sprung will still hold ride height even if oil is leaking out.
Oh, and pressures, which is what you asked , should be online somewhere or in a Haynes, Clymer or Honda manual, don't think it'll be high though, maybe 10-20 psi, perhaps a google search is in order
And you should set pressures with weight off the front wheel, forks extended for accuracy.