stuttering fzs 600

[red98]

been having a play over the last couple of days,on the verge of putting the bike into my mates garage for him to sort out but thought i would just check the things i have done including the mixture screws,i can just about adjust all four with carbs on the bike but slipped the carbs off just to make sure....best settings are 2.25 and ive taken the new k+n out and refitted the old hiflo filter and there is an improvement......worse with air filter out...going to check carb balance next to see what that tells me........back of my mine iam thinking ....rolling road,dyno