For all the K1-K4 owners I have now found the cheap clutch fix.
Normally with high rpm drag style launches the clutch judders and usually engages to early and doesnt allow the rider to slip the clutch all the way to the end of the clutch lever travel.
Grab one of these from your local Kawasaki dealer.
plate - clutch
(from a 2004 ZX10R)
It cost me $17.30 AUD, (ronayers.com has them for $7.47US)
I just installed this new clutch cushion where the 1st steel was originally (towards the inside of the engine) and discarded the original suzuki wave washer & seat. so it went:
FIBRE, NEW STEEL(13089),FIBRE,STEEL,FIBRE,STEEL ETC,
My clutch works great now. Last night I did a couple of 1.69sec 60ft times, I need some more practice but before I could do any better than 1.73
The clutch now performs 100%. I recommend this mod to anyone considering buying a Brock Davidson Clutch Cushion and this is much cheaper and probably does the same job!
Keep an eye on the clutch stack height too. Factory specs are 1.885"-1.890" (47.88mm-48.06mm)
The new judder plate measures 3.8mm thick fully compressed, the factory steels are 2.3mm so the plate will give a bit more in the stack height.
My clutch is a bit worn I ended up with 48.6mm total with the new zx10 steel in there.