06 Yz250 fork valving.

Im working on valving my 06 yz250 I bought used. I pulled it down and the mid valve is stock but the base valve is 

30x.11 x11

28x.11 x1

26x.11 x1

24x.11 x1










......... Where stock is


What would the 30mm shims in place of the 32mm shims do? Im new to valving and this will be my first attempt, I have read alot on here and have learned alot but Just want to understand effect the smaller shims will have. I plan on going back to stock valving and adjusting from them but just trying to learn what I can.

They are softer , I would try the valving you have now , for a lot if riders they would prefer it

They are softer , I would try the valving you have now , for a lot if riders they would prefer it

Ok thanks. Ive tryed it but the front end has never seemed right compared to my 06 yz125.

It maybe just how the 250 feels , even with the same valving as the 125 and stiffer springs for the 250 weight it will not feel the same

I never have been a fan of 250s and that could be some of the reason, I am also a 220lb A class woods rider and prefer stiffer suspension so Im going to try going to the stock valving for now and see what it feels like. I realy just want to understand how different valving effect different things as it will help me understand how the forks work and what to change.

I am curious how do  the smaller face shims make the fork softer? To me they seem like it should be stiffer since the oil has less leverage on the shims and would have a harder time bending them, Or does more oil bleed around them as they flex?

The 30 might not fully seal on the piston face, like the 32 will, so that's likely a very soft stack...

Edited by Eddie8v

I was going to ask if the 30s would fully seal on the piston.  Around 1 mm is pretty common as a seat width, so 2mm less might be right on the edge as far as sealing goes.  I'm not familiar with exactly how those pistons look.


There might not really be more effective leverage because the location that the force is applied hasn't changed (same port geometry).  However, the smaller diameter could make the flow path "easier", especially at low lift, which would make it a bit softer.

I had a hard time getting my 250 to feel as good as my 125 when I owned both.

Ulitmately the 250 needs to be stiffer than the 125 by a good margin to feel similar, the increased weight and power change how fast you enter braking sections, also changing when and how you brake.  


The rear of the bike needs more low speed damping control than the 125 as well - as the additional power creates issues under acceleration, along with the added weight.  


If the 125 was what you wanted with the rear rebound set around 8 - the 250 will be better around 4-5.

But that's purely the compression Im talking about.  Both bikes hook up better with the rebound around 12-14.  While rarely am I running rebound isolation nuts (check valves), I always do on the yz two strokes - starting with a hole around 2 mm up to about 2.2 application depending.

The free bleed amount on that era of yz's is huge compared to the modern four strokes on any brand.

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