All the bike like to be flooded hot or cold in summer, so I do the same in winter and today. I have tried some and full choke both today and other times and it does not appear to make a difference. The A7 does not wet sump, but the Norton does and this is part of the reason for the fortnightly startup, as it is not too bad after a couple of weeks. Occasionally in summer the Norton does sit for two plus weeks and still starts first or second kick. I accept the oil is thinker, straight 40 in both, I waited for a warmer day today to start them because of this. Normally you don’t even have to heave on the Norton to start it just a light swing. There maybe no science to it just the foibles of old bikes and I suppose it counted as my exercise for the day.