I drove it about a quarter mile yesterday and noticed it was smoking a lot and it finally make a clunking noise, lost power and died. After that I couldn’t budge the pull start. Took it home and pulled off the belt cover and that was fine. Pulled off the starter cover and that was find. I was finally able to get it unstuck by hand. It would turn a bit but not 360 degrees as it would hit something inside. I think I higher have a broken piston rod. Do you folks agree and how hard is this to replace?