I realise it's probably too late now, but did you consider RM250 96-98 conventional forks as a replacement?

Springs should do the trick, .46KG springs should be what you need for the front (I've done a few suspensions for your weight) and .50kg for the Shock.

Keep in mind, the heavier oil doesn't change the stiffness much, just how fast the reaction is.

triumph406, on 09 August 2012 - 10:22 AM, said:

I did, however i would have to change my triple clamps and who knows about the caliper set up, and possible my triple clamp bearings, plus still order the springs and i figured by then i wouldnt be much of anything but out a bunch of money then, unless you know something i dont of course...

JCollins6695, on 09 August 2012 - 11:35 AM, said:

I went with .48 for the front and i believe 5.6 on the rear.  Rear felt sweet from the little rip i took.

Sorry to see this post so late but did you all ready order those springs?
I have a set of ATK brand springs in my basement that says they are 21.5 lbs which by my math is 4.73KG but I dont know if that is right. Maybe someone else here knows how to convert it.
They are for an 89 RM 250K but I think they will fit the RMX because I never had an 89 RM but I did have an 89 RMX.
I will be glad to send them to you for the cost of the shipping, if you still need some.

mxwiz, on 10 August 2012 - 03:29 PM, said:

Are they 21.5 lbs/in?  If so, that turns out to be around a .38 kg/mm spring rate.Thank you very much, however i did already place the order and they would still be pretty light for my weight.  I really do appreciate the generous offer.

I've been down this road recently when I rebuilt my 89 RMX. I managed to find some .46kg springs that fitted (using a spacer) but they were slightly too small internally (diameter ) and would rub on the plastic spring guide so I had to machine it down.
After doing this and rebuilding them I found them to be a bit disappointing they feel harsh over general trail riding terrain and after some research I found out that the 41mm KYBs were a bad fork even in there day.
Due to there design they are too rigid and bind up mid stroke, it's a problem with all first gen USDs so I found out, so I'm in the process of swaping to a DRZ400 front end at the moment wich seems straight forward apart from the #%£*ing steering stop needing relocating.

Wmc83, on 17 August 2012 - 08:57 AM, said:

My springs just came in today, i will put them in tomorrow but i am at the point that i just wanted to get something pretty close.  Maby in the future if i get more competitive i will look into what your doing, but for what i need right now i think this was the best option. (atleast thats what im telling myself haha)

So I shaved a little off the spring guides and put the new springs in and it rides great.  Before i rode it however, i was tightening the 4 nuts on the right fork that hold the front axle and the top right one snapped .  Anyone forsee this being a big problem?

03machstock, on 18 August 2012 - 08:35 AM, said:

Nope, consider yourself lucky.  Extract the bolt, check the threads, install a new bolt and hit the trails.

zig06, on 18 August 2012 - 06:52 PM, said:

Oh ok.  I was under the impression that the studs were not threaded in there that they were manufactured as a part of the lower for tube.  Sounds like good news for me.  Thanks!