As someone mentioned earlier, considering your size, I think you should measure the "sag" first. What you describe sounds a lot like you are bottomed out to start with. Softening the shocks (or spring pre-load) may not make any noticeable difference.......or make matters worse.I'm a big guy about 270lbs and 6'4" and when going down the road it doesn't seem to just hit the bumps it fell like it slams the bumps. So I'm going to try softening a little bit.
Just enter as a GUEST if you want. I doubt you would be able to log in unless you do actually register, do so as a basic member otherwise you gotta pay. If you go to the start page there is a ton of info for the LC 1500 and C90, but for now click on "guest" and "start reading". It is a different format as MJ but you will get used to it. Lots of cool sig pics as well.What size spanner wrench ?? Also Frost I tried that site the page is set up really wierd and diifercult to get around but it could just be me