This 2004 Kawasaki ZX-10R came in with an intermittent running fault that dropped it onto three cylinders. It had been in and out of the supplying dealer on numerous occasions, with no result, so in the end made its way to us.
We did some simple tests to confirm that the problem was a real one – and it was. It was perfectly fine when cold, but when it got warm it slipped onto three, at which point it was hoofing fuel in.
So then it was just a case of working backwards from there. We traced it back to the Power Commander, which appeared to have developed an open circuit, allowing it to leave the injector open. We took the PC off (it’s basically scrap) and the customer’s taken it away with him; the bike’s now running fine. As he’s only got a can fitted, we ran the bike up on the Dyno to check the fuelling and it was ok – so he’s going to come back sometime in the future and have another Power Commander fitted, as well as a full exhaust system.