Waaay back when, I had a '66 Formula S, 4spd. Lived in Vermont.

In the cold of the first winter I had it (used) I would go out to start it and let it warm up.

Push clutch, start engine. Let clutch out, it would stall the engine. Had to rev it up, ease out the clutch.

I checked around, then drained it and put dexron in. End of problem.

I "believe" all the other four speeders that I had were factory filled with dexron.

The 4 gear in my VL21 will have 80/90 if it ever gets on the road, now that I live in Fla.