Its a sub 250 dollar chainsaw, if the price of a new one makes you cry then you have bigger issues.You guys saying to just buy a new saw must have deep pockets.
Looks like a oem engine is about $100, aftermarket under 40. I agree, the crank is most likely compromised either from lack of oil or debris, or both.
I applaud the father/son project moment, do it right and you guys can go cut together when life allows. Next up how to sharpen a chain and why some chain is better than others for different tasks!