Earlier this year my bike started sounding more and more like a Harley. At first I liked the throaty rumble, but after a while it got annoying, so I stopped turning the radio louder and instead looked at what the problem was. Here was the cause:

Too cheap to immediately buy replacement pipes, I tried exhaust pipe wrap. Looks pretty good, right?!

Unfortunately, the pipe wouldn't get hot enough to "set" the wrap, and I blew it off the pipe after a 10 minute test ride. Then I tried this putty stuff. It comes in a cylinder about the size of a roll of pennies, and you pull off a piece, mix it by squishing it around in your hand, and apply like you would bubblegum. It worked great!

At under $5 for a cylinder of this stuff at Pep Boys, you can't beat it. Make sure you prep the metal before you apply it, or it will bond well to dirt and rust instead of clean metal. I prepped with steel wool, which worked well. Also, work in good light - you need to see if the putty is mixed well, or it won't set properly. I still need to get some replacement pipes, but this really took away the necessity of doing it immediately.