Causes for solenoid to burn up

[Brushwacker]

Actually happened about a year ago, i have an old international industrial type tractor, time to fix it. Last time i used it ,started it , drove to the wood pile and loaded the bucket with wood, then drove it anout 300 feet to my porch, unloaded the wood, i had never shut it off from the time i started it, by now it was half dark or more and was on my way to the barn and noticed a light glowing i thought which was my solenoid burning and melting. Thank God there was snow to cool it off with (its mounted on te gas tank),had to disconnect a battery cable to get it to altogether quit burning.
I don't know if just a short in the solenoid caused it or what other sources could of been the culprit? May be the ignition switch stuck in the crank position but i think it wouldn't of run that long without burning up?
I am not very good with electrical so would appreciate some good coaching from those that are. I want to cover all bases so it doesn't happen again.

 

[buzz sawyer]

Does the tractor have what some call a "startenator" Generator and starter are the same unit or does it have separate starter and generator?

Could be a short to ground on the output side but you should have seen wires smoking too.
Have you checked for voltage to the input side? If there is voltage only while cranking, the solenoid could be sticking internally due to dirt, rust, or weak return spring.
On some, the outer cover was removable so you could watch the action.

 

[Brushwacker]

I don't think its a starter generator. The solenoid is pretty well melted.
Replacement solenoid needed for sure. Thinking to replace battery cables and contemplating replacing the switch assy also.