Fixing/repairing BMW's has been my living for the last 26 years And i do this test on many bikes on a weekly basis, most weeks more than once. The only reason it'll run like shite is if one of the coils has or is failing. You do realise we're talking about a 1200, which doesn't have a secondary or primary coil. It has 4 coil sticks. You can tell which stick has failed as that's the cylinder which doesn't fire or run properly as you're taking it in turns to run each cylinder in one coil stick. .