K3 Misfire
 

I went to start the bike this morning, and it was only running on one cylinder. Found that the front spark plug wasn't firing. Replaced them both. Now both cylinders are firing, it idles well and revs clean/smooth up to 4k. Above this it's misfiring and tries to cut out.
Fuel and air are getting to the cylinders, so i am certain the issue is spark related. Unless the fuel is flooding the cylinder?

Next on my check list is the Coil packs and HT leads. I was going to use the testing method from the Haynes manual. Is this test accurate, or is there another method that gives the same result and will flag up if the issue is HT Lead or coil pack related?

TIA