spluttering, flat spots and finally a failure to start

I really wish i'd changed that plug 8000 miles ago when it was due.

my bike was being a bastard this morning on the way to work, then it ouldnt start so i had to bundle it in the back of the car. (grr hate cars)

 

That'l teach you not to carry a spare plug an plug spanner

 

sounds like plug,if not then most likely the ht cap

 

i susected the same, replaced both, spark there but still no bang. (see the topic in workshop bit)