I got a aftermarket spark arrestor on my 400ex awhile back and one of the bolts started backing out and when I went to tighten it down again, the bolt snapped! So now half of it is out and the other half is still in the muffler. I took the spark arrestor back off because of it. Any ideas on how to get the broken bolt out of there? I just know it is like to be a pain in the arse to get out too...