Engine doth eaten it!
Developed a misfire a few days ago only on low revs under load, checked the dizzy cap & rotor they were fine and I knew it couldnt be the new leads. Next checked the plugs and to my surprise and No.2 sparker was missing its earth electrode!
What a nice down to earth engine you have.
Must of spat it right out the exhaust valve as it's happy runnings now :D