XR650L: Does Removing Emissions Controls Improve Performance?

Denver wrote to find out if the emissions controls in his Honda are hindering its performance - will it?

Just got an '08 Honda XR650L last week and I love it. Did a 50-mile ride on mountainous single-track and it performed great. The factory engine runs like a dog and I need to do some work to get it running smooth. With all the emissions requirements Honda has to meet, they've installed all kinds of excess tubes, air pumps, etc, which make it run poorly--all kinds of hiccups, burbles, and lag in low end throttle. If anyone has any suggestions for ways to improve it, I'd love to hear it.

On the Honda XR650L Parts page I read that a "block-off kit" for emissions control system didn't help performance, and then found http://www.4strokes.com/ that looks like it's got a good forum for the XR650L with talk about muffler mods.

It's worth noting that the motorcycles we love, even though they're great for saving gas, are really bad guys when it comes to smog. Susan Carpenter reports, in her LA Times Throttle Jockey column, that a

. . . surprising level of emissions [spew] from on-road motorcycles and scooters. In California, such bikes make up 3.6% of registered vehicles and 1% of vehicle miles traveled, yet they account for 10% of passenger vehicles' smog-forming emissions in the state. In fact, the average motorbike is about 10 times more polluting per mile than a passenger car, light truck or SUV, according to a California Air Resources Board comparison of emissions-compliant vehicles.

Best case scenario, you'll be able to get both great performance and keep the emissions control system. If anyone can help point out the best forum or listserv for the XR650L, please use the comment form below.