I have a 10424 or had… It seems the big end of the connecting rod let go. The rod bolts did not come lose, as the halves are still bolted together tightly. It poked a hole in the front half. Looking threw my new inspection hole I figured I probably could just polish up scuff on the crank add a new rod and weld up the hole. Boy was I wrong. Hopeful denial was crushed upon opening up the little engine… not one salvageable component in the short block.