I couldn't get a spark yesterday, so went off to old Harwich, to a motorbike shop, and got one...and a box spanner to fit it. Progress. Got back and still no start...it didn't seem to be drawing fuel, so I did something I have never done before...I blew into the tank ( by reversing my syphon) and that did the trick...filled the carb. But still no joy.
Craig, a heating engineer who flies a Quantum, tested continuity on my magneto with his multi-tester and that and all the other wiring seemed ok, so that we wondered if it might be the ignition unit, which would have been a simple replacement (and hopefully cheap)...but finally we tested the start again and it fired up....but I impatiently killed it by moving the throttle before the automatic choke knocked off. My problem is I hate the vibration at that cold stage.
So we tried again and it fired and held for about 35 seconds before stopping again...and then I was running out of time; I had a date to get showered for!
So I packed up....but am now optimistic for Sunday. I presume the old spark plug was why I got no start at Xmas. All else is just because it has been standing for three months.