Spoke, nice bike!! Just like my old K12 that messed with a deer. The Remus hex exhaust you have is superior stuff, don't loose it. No longer available. Looking as hard as I can I don't see the restrictor in place in the end. I don't know if they can be ordered from Remus but possibly. It does take it down to very quiet but reduces the HP that the open unit offers. I did a dyno run on my K13 with out the restrictor and gained 3.5 rear wheel hp over the stock rocket ship. Keep in mine every 7 pounds off the bike or load is equal to 1 added HP in performance. You will get used to it and it is not so loud as to be nasty. Though it sings well at 8500 rpm and rising. When I first got my Remus I drilled a series of 1/4" holes in the restrictor around the outlet center pipe. This added to increased flow, but I said what the heck and took it out. It is on the shelf. Put the retainer screw back in the hole to save it and make it look normal.