Preload adjustments will not make your front stiffer. It only compresses the spring internally and raises or lowers your sag. You have a "Linear" spring in your fork and compressing it does not make it stiffer. You get a stiffer front from adjusting the compression dampening in to restrict the oil flow or by installing a heavier spring.
Also, I suggest you not go by ring count on the preload but run the preload adjuster all the way in then counting the turns as you back it out to your desired sag setting, making sure both forks have the same number of turns. Use a socket and mark the 12 o'clock position with a shapie so you can easily count the revolutions.
Proper sag on your busa forks (Street use) would be between 35 & 40 mm. IMHO of course. If you dress out at 200+ pounds I doubt you will achieve 40mm.
Adjusting your suspension is not a difficult task but it is important to know what each adjustment does and the effects it has on the bike.
There is another equasion most guys don't take into consideration when setting up their bikes suspension, "Swingarm angle"! Without trying to explain how it all functions in detail, swingarm angle is extremely important. Expecially when dealing with the massive power of the mighty busa.
