Thanks, guys!! ---I did get a chance between rains to do some testing on the 20, and with regulator off, the center terminal (B+), has near battery voltage in it with key on/engine off. Just barely found a speck of white paint on 1 outside wire of plug, so I used that as negative and the other outside wire as positive, then started engine and hit wide open, looked at ac output and it shows 40.5 volts!
From the video, that would be spot on, so regulator must be bad. In process of ordering a new one.

I wasn't looking forward to having to take engine out to replace the stator, or magnets, so maybe I got lucky this time.

Now if I could get the driveshaft off the gearbox on the sunstar 18 so I can replace the front oil seal in it. Have cross bolt out, tried to drive it off, ( didn't hit super hard as gearbox is luni), and no budge. There is also a keyway showing in the end of the shaft.

It also needs the electric clutch unstuck on it. Last summer it started screeching when dis-engaged , so don't know what that will take to fix.

If I get these 2 in shape, it will help a lot on having some dependable mowers to last all summer without having to work on 1 right then. The old Craftsman 19.5 hp 42" jobber is doing good so far, but I used it hard last year.

"A machine you build yourself is a vote for a different way of life. There are things you have to earn with your hands."