thanks
no pressure then.....
short update, fixed the clutch and it wouldn't start. I unscrewed the spark plug and saw this
looked in the plug hole and it's totally coked up!
cleaned plug, poured fuel into the bore and it started briefly.
So next I cleaned the carb - inside and out it's a Walbro one, in reasonable nick. Not very dirty, but did have water in.
result is it starts again, next job make it start on the key