I now see you posted a drawing ..I was right THATS NOT GROUND ON START BUTTON THATS THE BUTTON... AND THERES YOUR PROBLEM... Look at the spark plug on your drawing see the symbol for grnd now look again at the button ..See the difference.if you put grnd in that circuit on that side well were having Blk 24 gauge for lunch well done..

 

Hey guys thanks... well I was looking closer in the battery box and I did find something... a ring connector with a tiny bit of black/yellow and a plug had been plugged into a white wire... which was then connected to POS on the battery. So giving Hot to some part of the the ground... surprised it didn't melt the wire.... in any case I switched that plug to an available B/Y wire (also found in the battery box)... and violat! start button works - turns motor. OK but now the battery is weak (charging) so not started up yet... but getting a lot closer. Cheers!