Thanks BT and Max for your input, If all I need to do is align the marks on the camshaft gear and the crank gear as per Big Teds video than I have that right. I was thinking that as the big one goes around once and the small one goes around multiple times than maybe there would be a single starting point. Once again thinking has resulted in a red Heering. I am guessing that my valve lapping has reduced the valve clearances and I can fix this by putting a file in-between the valve stem and push rod and wearing them down a little
Max's suggestion of a new coil is a good start, but I may have to wait awhile to come across one. I have checked the crank shaft key alignment and found it was a fraction out, so I removed it and although the key is in pristine condition there is a little room for movement, so I have reinstalled it resisting the temptation of holding the flywheel when tightening the nut, so it is pretty straight now. Picture is from before. Not sure about Max,s suggestion that I should not run it without the blade plate attached, can't see why that would make a difference but I will put it back on and see what happens.
In the meantime, as I have assumed that only 50PSI compression was my problem, and that may not be the case, I have good spark (but lacking the technology or know how to shrink the video file size so all I could do is shorten the video), the possible explanation is that I have put the electronic ignition in incorrectly. I have used these twice before (a Stihl chainsaw, and a very old B&S) with excellent results but this was a different module from a different supplier and the instructions were a little lacking (just a picture). As there is only two ways it can go its a 50% chance that I got it wrong.
I will give that a try while waiting to come across another coil and keep you posted.
If I can get a large enough hammer it will run for awhile just trying to get away from me
