To my ears I really didn't notice any detectable difference at all noise-wise, nor any difference with it starting or running.
To be fair, I pulled the damn flap out almost immediately after buying the bike (within 1,000 miles), so I never really got used to it's stock sound / performance.
Originally Posted by DSTEVENS
Hey Dan, just wondering about removing exhaust valve, does it start or run different? I like the idea of more noise, I love the sound after mine gets hot, it seems to make more noise the warmer the outside temp. I started it under the gas station roof after 3 hours of 80mph in 106* temps and I thought muffler had came loose it was so loud. Excuse hijack please