I have tried contacting White Brothers, however they are not very eager to respond to customer's correspondance:thumbsdn: I have the E2 for my 06'WR450 and usually run the exhaust fully open. On the last ride I decided to give it a try with the spark arrestor endcap to try and feel a difference over fully open. I noticed that when it is fitted the spark arrestor is faily loose between the muffler and the cap. It actaully rattles around in there. Do any of you E2 owners have this same problem? Is it normal?