I bought a fs90r spring of 09. late spring/early summer this year my cap became almost impossible to get off and a pain (at best) to put back on. I had to get supplies and told my stihl dealer (only use stihl) about the problem and not more than a week later I had a new cap on the machine that works great. The mechanic told me that if you ever put the caps on and they are even a little "off" of the mark (notches you line up) you can end up "spreading" the cap apart causing all the grief we've all been through. I dont understand why you cant just call your dealer for a new cap??? I love my stihl dealer and wont use anything else for trimmers, blowers and edgers.