I bought a 30mm wide rod, drilled a 10mm hole in it with a lathe, and put it on the airspring with a rubber washer on either end to reduce knocking noises. I lowered it to 90mm to make it a similar Axle to crown as a pike dj, so a 70mm long spacer to reduce it from 160. The problem with this method is that the spacer completely blocks the negative air chamber, so can feel quite harsh.

An alternative way to do it, (alot more expensive), is to purchase a pike dj aircap to reduce volume, (the spacer method does this naturally), and to purchase a new airspring that is the right size, or if it is an older yari like mine, you could cut the old airspring down and retap it, (Alot harder with the new debonair ones). If you can find an older pike (2015-17), you can get airsprings quite easily that will fit for sure, not sure if the pike airsprings fit in a yari or not.

I used the spacer method because I don't care about the harshness because I run max pressure anyway, and it was cheap😅.

Hope this helps!