01 MXZ 800 reed cage separated and is coming apart. Just wondering what could cause this. Also I ordered V-Force III to replace and wondered if I should leave the reed spacer in with these.

This is a common problem on your sled. The rubber delaminates from the Al cage.

Many people have gotten them replaced under warranty. The previous owner of my sled was able to get the new HO reeds/cages under warranty.