So this weekend I changed my plugs and air filter (which was black) on my 03 gsxr 600. Has 4700 miles on it, and WOW what a difference it makes in how it runs and idles!!!!! It was incredibly easy (only took about 1hr) and parts were about 32.00 20 for plugs and 12 for air filter.
Deff reccomend people to replace the plugs and ir filter at or arround 5k!