X55 for me now for 9 months or so. Love it. Just a few days ago my throttle was messed up. There was a distinguishable "clunk" feel in the middle of the forward/back axis. Opened up the back of the unit and found that there were two plastic "supports" or something that were broken.
I ended up making the holes of the remaining part of the support a smidgen bigger with my drill and placing a trimmed to length nail (as in wood) that was the same height and head size that the original "supports" used to be. Works like a charm again. Just a word of warning, be gentle on controls when possible and don't yank on the throttle to hard. If it feels too stiff and the tension wheel doesn't help, there is a youtube video of a guy who opens up the back to trim off some of the mollasses like substance used to give the user resistance. (
https://www.youtube.com/watch?v=g02dch8aZls). Wanted to see someone else open it up before I did!
Oh, and hello all, first post here.