Chris, I just had a thought. My arrow hold down spring had excessive downward pressure when I bought the bow new, I mean it was way too much, so I would check that, and also try to determine if the smell is coming from the arrow rubbing or the string. I know aluminum nocks can cause a gross smell. On my matrix 350 LE I had to pull up on the hold down spring quite aggressively till I felt the tension was correct.