After swapping out the K&N for a standard one the bike now runs much better. The hesitation when opening the throttle at around 3.5k rpm has virtually gone. There is still a little but it seems very smooth with none of the jerkyness that it had with the K&N.
I also put the idle back to 1100 rpm, adjusted the throttle cable freeplay to almost none, tweaked the gear selector position and adjusted clutch and brake lever positions. It's starting to feel like my bike now!
Still to do:- inspect CCT and replace is necessary, clean TPS - is this straightforward?
Again thanks for all the help !
"Given the right tools, anything is possible"
2001 FJR1300, 2001 ZR7-S