I'm not familiar with the Stihl equip.
Any chance of it getting bumped and the recoil pushed into the flywheel?
When I first started using a backpack, I banged into a few things while wearing my Echos, hard enough to make me cringe.
You'll get your spatial memory ajusted to walking with one on after a short time.
look at the Craigslist pics and you'll see that a lot of folks make a few bumps with them.
take an honest look at the housing and see if you find any scrapes or other signs of damge.
If it's a used unit, could be that prior owner or employe/user banged into somthing or dropped it
and made some attempt to patch that didnt hold.
But the blame isn't what we're hunting here.
Just the problem and how to solve it.
Take a few screws out and see if you can tell what's too close or scrapes
and see if you can tell which way it needs to be shifted
and then ask what would hold it there?
