OK I have just what my title says. I have a ms390 saw. About 9 yrs old. Now I'm pretty good with them I have even pulled this one apart when the decomp valve fell apart and the stem wedged the piston to the head. I have rebuild the varb and on and on. Anyway after I used it the other day I heard a metal clanking.I was alarmed so when I got home I pulled the muffler. I can see what looks like a metal cyl about the size of a 3/16 bolt shaft through one of the bolt holes?? It could not have come out of the cyl as the outer chamber appears sealed to an object that size from the motor side. Any ideas what it is? Having no idea what the insides of these look like I don't know and am not going to cut it to find out? Just running it as is but it sounds like there is something in my cyl or the rod is bustedwn I move the saw when off!