[Darren69]

Do you have any engine management errors, is the yellow engine system error light on the dash on or comes on at all? I'm thinking if it were a crank sensor issue then it would light (as I had an intermittent failure of that sensor) but then it would reset the next time.

I don't know the exact symptoms if you get some ECU failures, but again I would expect it to light up if there was a problem with any of the ECU Canbus sensors or the ECU itself had failed. I don't know what else to suggest I'm afraid. Was it running OK when you first bought it and this is something that has occurred since? Maybe the previous owner could shed some light on it with respect to the history of the bike? If its not electrical or injector related then it still suggests fuel supply or fuel pressure to me. Maybe the fuel pump is failing? Are you able to check the fuel pressiure? There is a pressure regulator so that could be something else to check.