I watch enough of Wheeler Dealers with Mike Brewer and Elvis to know that there is a lot of vocabulary that doesn't make it through translation from the Queen's English to 'Murican slang. Not many here know what an HT lead is.Family stuff and work got in the way of getting the bike back on the road but over the weekend I had a couple of hours to start again going through the wiring diagrams and checking some of those wires. I wanted to see if the bike would start so with the tank loose and raised on a block at the seat end I started the engine, fired on the button and ran perfectly. Then again later. Next day the same thing, not a blip on the throttle. But when I fastened down the tank and but everything back together and started the engine the RPMs dropped and it soon started popping then back on one cylinder. The front left plug was wet. I know that these early models are prone to grounding issues so I will do the ground check a third time and double-up on grounding wires where I can. If it isn't a poor ground somewhere then I'll have to find what is affecting the spark to the front left plug. I've ordered a roll of HT cable and replace the lead to the front left plug in case it is something a simple as a failed HT lead. I've ordered an inline spark tester too, just to make life easier. This weekend I will get back to finding the fault.