TOPIC:

Just a thought,.... if the carb wasn't getting enough air or fuel, wouldn't that affect cylinder no 1 as well? I only had one cylinder not running.... which to me points to the spark.... and no 2 spark in particular, or the lead as if the coil was bad, it would affect another cylinder too.

right, ok, that makes sense re 'shorted' plug. 

not sure if it was shorted, it looked OK and when taken out of the cylinder, it did spark.

I have no idea how that broke. I had some intermittent misfiring and when I took the leads off, the top of the plug in no2 came with it.

Ok, so I left the leads as they were and changed plugs 2 and 6 over after doing a compression test where all cylinders were 110-130 and took it for a short run... seemed OK, so not really sure what happened there. 

I'll know more when I take out on a longer run, but with the lovely summer weather we have been having here in UK that may be a while... :-/

Paul