The coil needs to be earthed by the wire with the loop that is normally earthed with the bolt that holds coil to the frame! Had the same problems as you before on my mates 04 270 ex dibbs bike! got a new stator and cdi from lampkins fiited stator first and still no spark! stuck cdi on and it fired up straight away! luckily lampkins let me bring stator back and just paid for cdi!