Well, a little progress to report...
I replaced the plug with a new one and filled-up with new fuel (with a stabiliser added this time)
It started on the first pull, but only ran for a few seconds and smoked quite a lot. Now it's back to its usual good imitation of a dead lawnmower.
The spark looked better with the new plug, but I'll test it again when it gets dark and I can see the spark a bit more clearly.
The plug seems to get quite wet, although I wouldn't say it was so wet that it wouldn't work.
Any ideas?
Mike
