Cbr600 f4 ultima light won’t Rev past 6k
 

Hi, bought an f4, it’s done 16 k full Honda service history, but been sat for years, owner didn’t notice or so he said that it was only running on two (1&2) sent it for mot, past with no advisories, so I took gamble rode very rough getting home would not go past 6k revs, so took carbs apart but only cleaned bowls and jets but then snapped off a pilot jet so bought a stage two jet set with 138 main jet and 42 pilot put it back together and fired it up it instantly fired on all 4 but took out and still won’t Rev past 6 k really so balanced the carbs, sometimes runs really nice other times bit lumpy, do u think That jets are Ok ? The book says it has different jets for 3&4 cylinders, i put Hiflo filter on and it’s got an end can Or do u think it could be coil packs At fault I had plugs out and checked for spark no 4 seems Slightly weaker than the rest Or Is it fuel issue? Do I buy a standard set of jets ?
many thanks