Earlier this year I successfully sealed a leak on my petrol tank with POR15. Delighted I put the tank back on and started the bike

.
I was unhappy with some cracking sounds so I rechecked it and found nothing. Now the bike will not start. I have checked the valve timing, ignition timing and I have a nice spark that the plugs are wet with petrol.
At my wits end I gave up with disgust.
So yesterday I bought some new plugs, drained the petrol from the newly lined tank, striped and cleaned the carb and put a gallon of fresh petrol in. It started first kick. Wow I am back in business or so I thought. Today I went to sort out the tick over and air screw. The bugger would not start. New plugs and still it did not start. I began to wonder about the petrol.
I put some of the original petrol in my lawnmower and it runs badly with smoke.
So does anyone have experience of the tank lined with POR 15 spoiling the petrol?
John