1984 Suzuki SJ410 Cold Start and Drive -3C 26F

I haven't driven this for ages, and it started OK during recent cold snap we had, sorry for dodgy camera angles. This is a completely standard 1984 SJ410 with four speed. The heater heats up to full temperature in about 2 minutes, it's fantastic in the winter, and is a (slow) workhorse - it was fully rebuilt a couple of years ago, with pistons rings, bearings, valve seals, pumps, etc.
These 1000cc F10A engines are very reliable, I've had three - one in an SC100 "Whizzkid", this one in my SJ410, and an F10D in a 2004 Suzuki Alto (with fuel injection and 16v), which was meant to go into one of these SJ410s.
The carburettor ones suffers badly with momentary fuel starvation on corners, especially on the SC100 because it was mounted sideways in the rear. MY SJ410 always stutters on the corner at the bottom of the road, everytime!