setting WP piston height on '13 250sx

Since there are still no service manuals for '12-'13 250sx's (ktm = slackers). im in need of setting the piston height on my 2013 linked bike. when i removed the stock sealing bolt and bled the n2 out, the piston was 96.75mm in depth from the reservoir sealing surface (where the little allen bolt sits). i drilled and tapped the reservoir for a schrader valve. i had to remove the piston to clean the shavings of course, so:

a ) is this where piston height is measured? or is it done from the larger allen bolt near the HSC adjuster?

b ) is it ok to just reset to 96.75mm and then continue building the shock back up? or do i need a different measurement from the larger allen bolt?

c ) what is the stock n2 pressure setting for 2013 wp shocks on SX bikes?

d ) what is the torque spec for the shock valving retaining nut? i want to say 40nm?

e ) what is the torque spec for the fork mid valve valving retaining nut?

Edited by mynewcr250

Hi there,

a+B) Piston height is measured from pushing the piston completly in from the N2 fillinghole, taken that number and subtracting 10mm of it.

ex: piston pushed fully in measured distance from fillinghole 103mm. After filling up the shock you push the floating piston in for 93mm

c) 10 Bar

d) 45 Nm

e) 5 Nm


I use 13mm from bottomed out

Remember you have a top out spring as well!!

Service manual is saying 10mm. Going to 13mm to create a security?

yes more room for error

You guys are awesome. I searched Google with no answers, took 1 minute to make a post here and have exactly what I need.

Quick question for ds1434, I'm trying to wrap my head around what you're getting at. Are you saying I need to compensate my piaton height due to the fact that the top out spring will be compressed at some points during the stroke? Where do you prefer to set piston height as opposed to mog and prodigy? You may remember me from ktmtalk, you threw up a stack for me to try in my revalve thread. I also made some small changes (more low speed and also some more rebound to try and control my much heavier spring) to the shock. Will be trying it out this weekend if all goes well.

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