OK, so your in the UK that means a heavy 2K-3 ignition. You can experiment with some of the single taper needles, do a search and research the jetting forum. Yes, the CCK is one but I do not like to make blanket statements on jetting specs because if the rider is not savy on jetting he can seize his bike if conditions are wrong, so start rich and tune it in. Personally I have found the C series needles a little lean in the 250s, and have done better with the D series, but thats me at sea level. You can also retard your timing 1mm for a slightly softer delivery. Its easy on the 2K-3, just elongate the hole in the insert 1mm toward the rear, so the stator can be rotated 1mm counterclockwise.