The CS is not a high performance bike. It makes a calm 50 HP and 40 ft-lbs. That said, you can get a decent performance boost by doing a few things:
- Fuel Nanny. Techlusion is the most common. Feedback has been mixed. Some love it, some hate it. I (xxaarraa) have one and am very happy with it. Cost: ~$150
- Exhaust. Check the exhaust upgrade options page for details. If you have a nanny, the exhaust goes nicely with it to get the maximum boost together. Cost: ~$350
- Air intake mod aka snorkelectomy. Check the air intake mod page under custom modifications for details. Again, goes hand in hand with improving breating - nanny + exhaust. Cost: ~$5
- Iridium tipped extended plugs. This is more a cure for the stalling/surging problem, but cannot hurt performance, so I will list it here anyway. Cost: ~$8
That is pretty much it. That should net you noticeable power increases. I wont quantify what "noticeable" is, but my guess is ~ 5HP or less.