The fuel filter is integral with the pump and is not a maintenance item so if the filter gets knackered then it's off to the dealer or replace it yourself. Our friend Asif, from GTR1400 site in the UK came up with this lovely procedure to change or clean the filter. Please note that if you go to that site, I believe that you have to join to see the posts.
http://www.zggtr.org/index.php?topic=17490.0 Procedure to change/clean the filter
http://www.zggtr.org/index.php?topic=17480.0 Tank bolt torque
http://www.zggtr.org/index.php?topic=11973.msg146354#msg146354 Fuel Starvation
http://www.zggtr.org/index.php?topic=10140.msg123527#msg123527 Engine cutting out intermittently