One further easy thing you can do Gerry is to check for continuity between the brass strip on the slipring that you can see with the pick-ups off, and the body of the mag/earth. Should be, say, 5000 ohms typically. Anything from about 4K to 7-ishK ohms is possible. Mega-ohms or Open Line is bad and says the connection from slipring to coil is bad, or the coil has a break (or, just possible, that there isn't a good earth brush connection). If the coil was rewound as part of the recent work, there shouldn't be a problem, but you never know, stuff happens. Seems as if your low tension side is probably working OK, but worth checking the condenser isn't shorting, especially if it's a steel cb assembly, and also, if it's steel, that the blade spring on the opening point isn't touching the camring in certain circs. That'll kill the low tension stone dead. You can do a very basic check on the condenser by holding the points open with a bit of something (with the cb off the mag or the centre screw detached) and putting a meter - on its highest resistance scale - across the points. The reading should rise rapidly to Open Line, as the millivolts from the meter charge up the capacitor. Also, if the pick-ups aren't new, they could be causing a problem. Dare you stick a finger on them, with the engine running (if it will)? Any tingles, let alone visible sparks or arcs, bad. Anyway, good luck with it. Cheers, Bill