Onan Microlite 4000 shaft locks up on occasion

I’m not arguing with anybody. Onan had to move to 3600 rpm from 1800 rpm to stay competitive in the market for generators that’s the name of the game. They are not made like the Ws3 or the Cck that were made to last forever.
I’ve seen a spec K microlite piston rings stuck on the ridge, if the Op can’t find any reason it’s getting stuck he needs to pull the head and look at the piston. As is posted here It could be anything.