I have 06 F4i and just ordered ram mount x grip stem kit.
when i tried to put the stem rubber, hole is too big and deep so it just move around
how did you guys install? Any advise?

 

What I had to do was take the fattest end of the stem, and cut the rubber away around it with a razor blade, keeping the circular shape, and make it just small enough to make a snug fit into the stem. Without losing the cut rubber piece into the stem, attach the rest of the mounting hardware and shove it in there, and tighten it down till its solid. Mine hasn't moved even after a high-side tumble destroying my phone and the x-grip itself, but the mounting itself is still solid.

Hope this helps.

 

I had a similar issue at first when I tried installing the RAM mount on my 02 F4i. I wrapped a few layers of electrical tape around the rubber stem piece so that when I inserted it into the hole it was snug enough but still had enough room to be tightened and expanded. (By turning the center bolt in the rubber piece) The tape will compensate for the lack of thickness and it'll remain inside.

It may not look as elegant and it vibrates a bit but it has stayed intact and has survived a crash as well. (My phone was even still mounted afterwards!) I think if you take your time wrapping the tape carefully you'll be able to get a similar result as installing it on other stem mounted bikes.