Here are the links to all the details, its a long read but alot of the usual peanut gallery noise. The guy that seems to know some stuff about 4CS (Terry Hay is a auzzie tuner) so really pay attention to his posts.
https://thumpertalk.com/forums/topic/11 ... cs/?page=2
http://ktmtalk.com/showthread.php?50891 ... rk-answers
Basically I did this
- remove check valves
- drill 1mm hole in midvalve
- instal Race Tech gold base valve and comp adjusters (Kit 280601G and FACB M3010001) as per install instructions
- reassembled with same preload and oil hieght as before mods
So the rebound will then be at the top and compression will be on the bottom. Do NOT convert to OC configuration!
You can do the fix cheaper but you will need to do alot more reading and sourcing individual shims seemed stupid expensive.
Building the bottom comp stack took some effort, the shims in the kit are not marked so you need to measure them with a micrometer or a really good caliper may also work. Took some time at the kitchen table to sort out
I am just using a recommened setup from the RaceTech but the base valves have alot of valve shiming options for the tinkers out there. I was so happy with the first attempt I never touched it again. I am sure it can be improved but after suffering a 100hrs on stock valving these mods seemed like magic.
When removing\installing the mid valve the threads on top of the inner rod must be covered or you will tear the small oil seal. I just used some teflon tape to cover the threads, other than that it was straight forward.