I post this at least a few times a week.....when the shoe fits!
And I will post under it every time that there are so many idiot morons who post total garbage on You tube that if you do not know anything at all you are more likely to destroy what ever it is you are trying to fix than fix it.
I bough the repair run 7 years ago and have been playing with vintage motorcycles all my life so was a reasonable mechanic.
However the actual mower & tranny repairs were all new to me so I did what you expouse, watched a lot of You tube
Even then it became apparent that I knew more than 90% of the clowns who post
As such the only You-Tube "EXPERTS" I trust & would advise others to watch are Taryl & Donny Boy and since being on here Steve's Small engine Saloon ( although drinking while working on mowers is 100% lunacy )
If You Boob was such an unbeatable resource , the be all & end all of mower repair then Adevo's mower would be making clippings by now, not sitting in her shop dripping oil.
As for Adevo, what she got from me was the plain answers to her specific questions .
I am mythed to understand why if she followed the testing proceedures exactly as laid out i the technical manual the problems were not resolved .
I have bought 7 JD technical manuals and will continue to buy them for each customers mower because they can not be beat.
They also caused me to revise my diagnostic proceedures .
Standing down from the soapbox & returning to planet earth.
I care not if you are a woman, man or child.
All get treated equally from this little black duck.
So your cranking circuit is fine because the engine is revolving and if it was revolving then there was no reason to touch the starter solenoid.
Your next step is to put a SMALL amount of fuel directly into the spark plug hole then replace the spark plug & crank the engine with the throttle fully open but not choked.
This is assuming that the spark plug is clean & dry
I use carb cleaner for this , not starter fluid like 99.9999% of You -Boob experts tell you to do because it can preignite and blow a hole in your piston or bend a con rod
Crank the engine for a good minute .
If it starts and runs till the fuel is all burned up then you know the ignition timing is good .
Next step is to spray a SHORT SHOT of carb cleaner down the carb while cranking the engine
If it starts and you can keep it running by spraying VERY SHORT shots of carb cleaner down the carb then your valves are good and you have fuel supply problem .
I will leave thing here to keep things simple , clear & concise thus avoiding confusion.
If you want help then please do this and post the results.
If you need to, use jumpers from your car to do this.
We can sort out the battery problems a bit latter on once we have your mower running.
And I am Australian so I talk plain & direct , no pussyfooting around .
Many Americans consider this abrupt or rude .
That is your choice.