I can't specifically suggest anything (SMB shopping and therefore reading the forum), except I do have a question about your description because maybe I have been mis-understanding "turn over" all these years.
You say it won't turn over, but then you describe it as:
Originally Posted by OttoVolcomSMB
Sorta started but sputtered and never really turned over.
In my mind, "turning over" has always been what happens when you engage the starter and you get a "arump, arump, arump" sound before
the engine fires at all. Thus, only after it has turned over can it start at all, even in a sputtery, unhealthy way. OTOH, if you have a dead battery or bad solenoid, no "arump, arump, arump," but rather maybe just a "click" or "nothing," so there is no turning over at all.
Maybe my definition of "turning over" is not correct? On the other hand, if I do have it right, and your SMB ran briefly but sputtered and died, then maybe it did turn over but would not start or run properly? Perhaps the distinction would help in diagnosis.
I hope all is well with your SMB after its solo night.