Lean jetting leads to long warmup times, surging, and balky throttle response.
Then add a less-restrictive exhaust system, and your marginally too-lean bike is now less happy.
Cobra has a selection of jet kits that can transform your bike's manners.
By tailoring the jetting of your bike's carburetors for your local climate, your exhaust system, and your style of riding, it's possible to have a great-sounding, great-looking bike that also happens to perform great, too.