Further research reveals that 70 was also a stock main jet on a towny. Maybe one of my three had a 70 in it. I can't remember.
Two of my Townys were white. I replaced both crank seals on the first one but it was always running around 370F-380F. My 2nd one - I replaced just the left crank seal - I could rarely get that one above 340F. A buddy sent me a Towny engine to put a Malossi top end on with a vm20 carburetor. That one ran in the 340's. Must be that 2nd gear taking the strain off the engine.
That last one was a dream Towny. It did 43-44 with stock exhaust and I could cruise through the neighborhood with the throttle barely open and it's doing 35 in super stealth mode. You might of thought it was an electric scooter or something. I didn't have it long enough to play with the jetting more but maybe it could've eeked out 45.
I've got just one Towny now with 60cc kit, vm18 and stock exhaust. I may try to replicate the Dream Towny set up with a little spacing under the cylinder to raise all the ports.