Just put some new parts on my echo SRM2400 and cleaned it up. Since it was apart, I decided to try to find the source of a very loud rattling that it has had for a while when it is running at anything other than idle. It makes it about twice as loud as it should be. All the bolts on the machine are tight and I even tried running it mostly taken apart. It appears to be origination from the muffler area. I took the muffler apart as much as I could running it without the spark screen in it, wedging things between the engine and the heat shield. Still, the noise persists. There doesn't seem to be much to the internals of the muffler that could be loose and rattling, but I can't figure out where else the noise could be coming from. Any ideas? I am thinking of just buying a muffler and seeing if thats it, but I don't wanna spend the money and find out thats not it. Think there is anything in the muffler that could be loose?