Quote Originally Posted by aimee_patterson
Will a tt K and N air filter fit on my speed four and would it make much difference??
Looks like it will Amiee,the part no. is TB-6000.
As for making a difference,not that you would notice on a standard bike,mine showed less than a 1bhp gain on the dyno.The main reason for buying one is that you never need to replace the filter again so its worth doing it if only for cost reasons.