BM D11 skimmer Q.... Muffler cap on or off?

[Shawn_S]

Got it all installed. On the silencer/muffler, there's a bottom plug with a black cap. Should this be on or off? I think it might be an ozone port, but not 100%. Most of the pics of the D11 online don't have it on, but just retailer photos.

 

[P-Dub]

Keep the cap on. It's doubtful it is for ozone unless the silencer is Ozone safe. Couldn't tell you what it is for though.