Norton not happy

So at the end of the working day I thought I'd take the Norton out for a short blast, talk about being huffy cause its been ignored, it farted and banged all the way to the shops, cut out twice so I left it to sulk in the car park while I grabbed something for dinner. It started reluctantly and farted and banged all the way home. I gave it some attention (new plugs) and it seems to be happier, I was going to treat it to some fresh petrol (which is probably the issue) but thought I'd see if it behaves first. Question is, should I put my shiney newly painted steel tank on it for the weekend (its been in the loft since I got it painted) ?