Posted by William Boylan on March 19, 2002 at 17:46:43:
In Reply to: Re: Muffler Comments, Please: posted by Mike M on March 18, 2002 at 16:06:46:
Mike: I didn't run the bike with the new muffler prior to drilling the holes so I don't know what it sounded like when unmodified. The new "modified" muffler is definatly louder and sharper "higher pitched" than the old, original muffler. It is not offensive, but is not the low rumble of older singles I have owned. I don't know the history of my bike, but, by the mileage, I assume the muffler I removed was the original. The bike had been laid down on that side before I got it, and the muffler was pretty badly scarred up. I have no idea why the difference in the diameter of the exit hole, but the old "original" one measures 7/8" while the new one measures 3/4". I am not sure what year the "new one" came off of, but it looks unused.
I don't pretend to understand the thinking behind back pressure, and the change may have been deliberate, at the factory, to enhance back pressure or for some environmental consideration, but in my experience with several sports cars and assorted other "hot rods", outlet shoud equal or exceed the header pipe.
I took the bike for a short spin after installing the new muffler. Not far, maybe a mile, (it's cold around here) and it sounded good to me and was definatly stronger.