40 year cold start problem...solved!

[LSRX101]

After giving Dads 107 some much needed love over the summer and locating a snow blower, I revisited a cold start problem that has plagued the tractor since nearly new in 1971.
It would start fine in warm temps but below 50 or so it didn't like to fire and was prone to flooding. Below 30 degrees it usually would not start at all. Cranked good but wouldn't start.
Dad always said the 107 was "cold natured" and had "always" been that way. Since it was used mainly for mowing in summer, it usually sat in the shed all winter. I always thought that those Kohler engines were "that way", and could be temperamental when cold. (I recently found that to not be true, my newly acquired 126 starts right up in the cold).
It recently got a new head gasket, points, valve adjustment, air filter and carb rebuild. It ran better than it had in years. Surely after all that work it should start in cold temps with some careful handling, Right? Wrong!
I went over to mount the snow blower last week and it wouldn't hit a lick. Just a few puffs of smoke and a lame cough now and then no matter what I did. The spark plug was soaked in short order. Dad smirked a bit and had a "told you so" look.

The spark was really wimpy and yellow. I've had much hotter sparks go from my finger tip to my car door in the winter!
Hmmm, the points are new so it has to be the coil or condenser. I've got 12+ volts to the coil when cranking...wait...no way was the coil or condenser "failing" for about 40 years!
As it turns out, one or the other was bad. My bet is the coil, but it was replaced in about 1973 for another issue and the cold start problem was still there, so...??? I had a GM condenser and an internally ballasted coil (VW I think) in my collection of NOS parts. 15 minutes to replace them and vrooommm!, it fired up It now rolls over one full revolution and takes right off, even below freezing.
I'll leave those parts in place and see how they do, I think they will be fine.
Temps here have been in the teens at night and 20s in the day, and Dad has been going out to the garage and starting his 107 almost every day now, just to see it start in the cold.
It just boggles my mind that a part could be "failing" for that many years and not have just given up totally long ago.

Still have to get the snow blower mounted. It's an early (Danco?) blower without the quick attach brackets. I had it mounted and working when the weather was better but had to remove it again to reposition the drive pulley (Stripped set screw and siezed to the shaft). I've since bought a house, moved and got busy setting up housekeeping. Now it's cold and Dads garage has no heat. It has walls and a roof, so it could be worse, though.