according to my clymer manual,the front forks can be pumped up between 5.7psi(standard) and 14.2psi(maximum). thats 39.2kPa and 98.1kPa.
the maximum difference between the fork legs is 1.4psi(9.81kPa).
if you had an accurate tyre pressure guage you can do this with an ordinary bicycle pump.
ive seen proper tools for doing this,little pumps and things for equalizing the leg pressures but i dont know if it is worth the money.
hope this helps.
P.S. my xt600e doesnt have adjustable forks, so ive got to change the springs and oil to make it harder for the road.lovely.