Hi forum
Hoping to get to bottom of an issue or two I am experiencing
Lots of missing (Brief surging power delivery interruption, stuttering) on acceleration

In addition and unsure if connected revs erratic and doesn’t always return
to idle Quickly
Will rev out and idle (although I do get a double rev, like a second smaller rev after initial rev)
So far have:
Burnt out exhaust
Chucked a new carb on
Sprayed wd40 around boots and behind timing plate ( as best I could)
No change in revs and idles well
Run breather hose into glass of water, no air bubbles
Chucked a new ignition coil on it
New plug

Will check points and try to look into timing Tomorrow, haven’t attempted this yet
Any pointers would be gratefully recurved
Maybe a coil or condenser going bad?
Many thanks
D

I had a similar thing and it did turn out to be the air-side crank seal. It was fine most of the time but under load and once the engine warmed up it was leaning out. Unless you've replaced it recently well worth trying.