First a stupid question. How do I now if my muffler has a spark arrestor? Secondly, I don't believe it does so I'll need to buy one to compete in our local hare scrables series. Does anyone have one for sale that I could get immediately. Or can someone recommend a new one. I'm using an FMF Power Core IV and am very happy with it. I was thinking of and E Series, or a Power Core w/ spark arrestor but I am open to suggestions. Thanx!