Do the plug caps (rubber boots) detach from the HT leads or are they integrated? (NC30)
I've had a problem with my No1 cylinder not heating up and I think I've traced it to a dodgy HT lead. I'm going to cut it back and reattach it if I can.
The carbs are balanced and the problem is only there at idle, does this ring any bells with any of you and would a dodgy HT come alive when put under load?

Any help appreciated.

Possibly number 1 carb pilot jet or circuit blocked.

Ignition more likely to fail under load.
The plug cap can be removed by unscrewing the center screw and removing spring and suppressor, then unsolder inner wire when cap is peeled back.

I would first fit plug lead number 3 to cylinder number 1 and see if that worked, to prove the lead.

Dave.