Recently i had a frozen chain adjuster on my 01 ZX12 on the Caliper Side. The swing arm had filled up with water on the Caliper side

and rusted the bolt from the inside.
Kwacka have drilled a hole in the rear of the swing arm on the chain side, but not the caliper side, so the caliper side fills up with water over time through a small hole near the where the swingarm mounts to the chassis. (over a litre of water came out

)
Solution: Drilled out the old chain adjuster bolt, heli-coil, replaced adjuster bolt, and drilled a smail 3mm hole on the underside of the swingarm to match the other side. Cant fill up with water now !!!
Recommend all 12 owners do this small Mod before you end up with the dramas i had