2022 Yz 125 midvalve stock for plusher fork.

You could try to reduce the oil volume slightly. 

Ideally you would to try a lighter spring, but it's free to remove a few ml of oil.

You should dump the current oil into a measuring cup to see how much is currently in your forks, that's your starting point.

Removing 5-10ml would make the forks more plush. (If it was me I would re-fill with new oil, 5-10mm less than the starting point).

You should check the service manual to find the recommended oil level range, I'm guessing it is something like 250-300ml.

What style of riding are you doing?

Hate to say it, but it's caught a lot of people out in the past including me... sometimes a soft fork can feel harsh. Try going in on compression to be sure.

If you are sure that softer is the answer, as above play with oil volume. I found 10ml increments too small to notice, so I tend to do 20ml at a time and then fine tune when I'm getting close.

Also don't ignore your rebound. It has a cross over effect with the compression, and a slow packed up fork will also feel harsh.

Thanks for coming back with an update. It's always great when we get a follow up on these types of questions. 

You might want to try slowing the fork rebound, if it's too fast that could make the bike deflect and feel harsh on chop.

Also, if you're not already, make sure to bleed the air from the forks. It's the flat head screw flush in the fork cap. The forks will accumulate a little air, especially from hauling, and that will make the forks a little harsh on the initial movement. 

 

Good move on the tyre pressure. Modern tyres are built around heavy, front loading 4 strokes. The 2 strokes, especially a 125 put far less pressure on the front and can be run much softer. I run 12 psi front on my RM125 with a Dunlop MX33 for reference.

Double check your sag and maybe try raise the forks in the clamps. Some extra front end weight may help you find that settled feeling. Don't go too far as to make the chassis twitchy though.

Once you've tried this and a slower rebound, if you still need more then a revalve will be the way to go. You could try 0.40 springs but 0.42 should be perfect for your weight. A slightly stiffer spring with softer valving is (personally) better than a soft spring with harder valving.

Post the mv stack to be modded if possible. 

The base and rebound stacks would help too. Your total stack height is 2.64mm, and that, IMO, is too aggressive and puts too much preload on the stack, causing the symptoms you describe. I like to keep it around 2.5-2.55 +/- and only go closer to 2.6 with the most aggressive riders.

I would suggest removing the 12.11 from the compression portion, which will reduce the total preload and make the stack a little softer, both of which will help the initial engagement of the MSV. You could leave it out or add it under the leaf portion of the stack, which will slightly limit how far the leaf bends into the cup, controlling the total port growth on the biggest hits.

I'm also not a fan of using two .11 crossover shims in the rebound stack. One 12.11 or 13.11 will help control the springiness feel without having to run the adjuster too far in, in turn affecting the compression circuit. 

I would also be interested in hearing @m21racing 's opinion, as he is a very experienced tuner himself.

I tried to upload a stack i had, but if you know how to set them up, you should be fine with total stack height,  cup shims , and taper of active/passive shims. 

The total stack height was 2.59mm on the modded stack. The cup shims combined for a total of .5 height in cup.  (2) 20.1s then 17.11, 14.11, to a 11 diameter clamp. Like the 2012 kx450 stack, you'll want to use a series of shims to get total stack height in addition to your tapered stacks. You can try a pretty standard taper from face of piston to an 11 diameter clamp shim.  Hope that helps a bit. I've also used 2 stage base stacks on woods applications.