640 Solenoid?

I have a 1956 640 that developed a leak in the car - so when I discovered this I mover it out of the barn and parked it out in a pasture and ordered a rebuild kit.

Kit arrived, I replaced all the replaceables and when reinstalling I must have cracked the sediment bowl gasket as that now leaked like a sieve. And when I shut off the fuel and pulled the bowl the gasket fell apart in my fingers. Harumph - ordered new gasket.

Today I installed a new gasket and screen. Went to start the tractor . . . "click". I hear the solenoid click but nothing else. Took the battery in and charged it (12v negative ground updated system) and in 30 minutes it was full charge. Hmmmm. Reinstalled . . . "click".

Went in the house and got the voltmeter. Starter gets voltage, coil gets voltage, headlights light.

Pulled the starter, spins free, cleaned the contacts. "Click"

So I sent to my SUV and got the jumper cables and bypassed the solenoid by going right from the positive battery terminal to the starter positive stud. "VROOOM!"

I've never had a solenoid fail that was "clicking" and showing voltage to the starter.

Is there anything else it could be?

Sorry - should say it developed a fuel leak in the "carb".

I would clean and tighten all the connections.
Particularly both ends of both of the battery cables.
The ground connection to the frame is often a neglected point.

agreed, clean and check all connections.