I've got a fuelling problem with my 2001-model (A2) ZX12R, in that it runs far too rich. It's intermittent and you notice it as it runs jerkily or unsettled at light throttle just bumbling along at 30 - 40 mph. Get off the bike and stick a finger in the exhaust pipe exit and it's covered in a really thick, powdery layer of soot (much heavier than normal). This first started happening shortly after the bike was new, about two years ago. The dealer had it back in but never really traced the problem (although they absolutely agreed that the fuelling was miles too rich). They replaced lots of parts, including ECU, sensors and injectors. And that SEEMED to cure it (although it was intermitent anyway). But, two or three weeks ago I was out for a ride and suddenly it was running unsettled and making piles of soot in the exhaust - and using lots more petrol than usual. Up to its old tricks again. Any ideas out there? By the way, it's had its plugs replaced (and has run like this on three sepaarte sets). And I use a variety of brands of petrol - not from just one petrol station.