Or, if you like the exhaust note, just not the volume, you can quiet them down with a lollipop-like baffle. Just measure the ID of your outlets, then go to the hardware store and fine a gas pipe end cap that will fit with only a little clearance. Drill and tap 3 holes, and insert 3 set screws with socket heads; use a ground down allen wrench to tighten them in the pipes. I used this method on pipes that were too loud on all three of my bikes, Valk included. This is what one set looked like:
The more material you remove, the louder it gets, so start with a smaller center hole, and don't grind off the sides, until after test, then open it up until you get the noise you like.
Note the screws on this had heads; I ended up with headless screws for easier installation.
