I recently purchased a 98 WR400F and have absolutely loved it, tons more power then the XR350 that was stolen from me recently. I am getting ready to go to Colorado to ride in a national forest and my bike does not have a spark arrestor. It has a DSP Factory Series Titanium muffler on it which seems to be a decent muffler. I have done some searching but have had no luck on finding anything that will work for this system. If anyone can give me some advice on what to do or where to go I would appreciate it.