I've had trouble with mine also. When I took my Z8 in for some other warranty work I asked them to look at the seat belt also. They took it out and cleaned it up, but no replacement. It worked fine for about the first 50 miles and now it isn't working right again. One thing that I've found is when I pull the belt out of the spool, if I don't pull it out to the very end, it seems to work most of the time. What I am going to do is put the seat belt on to where it fits and then put a clip at the point where the belt goes through the ring, so the belt will not retract at all.