As they say, the devil is in the details. Started out the morning going back over all of the basics, looking for that one detail that had been missed. I decided to make one small test to verify the ignition was actually firing at the precise moment the timing mark was reached. I did that by removing the plugs, snapping them into their boots and putting them against the cylinder head, then taking my 14mm box wrench on the rotor bolt and gently rolling the engine thru the firing marks with the ignition on. So I began this process and as the rotor passed thru the LF mark, no spark!!!! WTF? So I continued to roll it over as I wanted to see at what point the Left plug WOULD fire. Oddly enough, as I continued to roll it thru and then reached the RF mark (it is simply marked as an F on the rotor) and then it fired. Suddenly it dawned on me. I had thought the coil was hanging somewhat lower than normal and had not realized that someone, at some point, had relocated the coil on the bottom of the frame brace and at that time REVERSED the plug wires. It looked so much like normal that I, like others before me, had missed this small detail. Doh!!!!!!!
Needless to say, I was pretty happy to make this discovery, and as soon as the wires were reversed, it immediately started!
It ran a little ratty at idle and seemed to be running only on the LH cylinder unless revved up, so I took the bowl off and found a dirty idle jet. Cleaned the jet, reassembled, and it was tiny bit better, but still not right. As it was running, I stuck my finger in the carb throat to feel the vacuum slide, on the LH it was moving freely with the engine load, but the RH was stuck in the up position. I can only surmise it was popped upward during one of the backfires. After pulling the carb top off and freeing the slide, it ran much better and idled smoothly.
To say this made my day would be an understatement. This afternoon I plan to tidy up the wiring and controls, soak the stock Scrambler fuel tank with vinegar for a final cleaning and generally start putting things back together and make it at least somewhat ride-able. Stay tuned for a ride report!
What would John Penton do?