I like it. It sounds like a big throaty four cylinder jap bike. Not the little 550 that it really is. I also got the rain flapper klinking noise I was hoping for. It's actually a lot klinkier than the video reveals.
I still have to seal the elbow below the muffler. I hadn't done this yet because I didn't know if I was gonna get the sound I wanted. I was happy to see that when I held the rain flapper closed the only place it leaked was at this elbow. My header collector seems to be welded up tight. Schwinnggg!
I still have the restrictor that came with the muffler. Of course it was removed before I ever started this project. Now I may use it to fine tune the sound and klinkability of the rain flapper.
I sat on the bike and revved it up a few times. I think it's gonna be alright. The outlet points away from me just enough so I won't be breathing rat fumes yet it's close enough for me to enjoy it. The fact that it points up may lessen the offensiveness of it's tone. I'm not gonna get into the whole "loud pipes save lives" debate. That's not why I built it.
So it looks like this project is a success and fine tuning it will be simple enough. For that it gets the Greasy Shop Rag stamp of approval.