So maybe someone here has a clue what I did wrong. A few weeks back I had a 21B807 2453-B2 with no power as the customer concern. 2009 vintage. Little old man , little old MTD rider. Valve action was quite poor, badly worn cam lobe. Would have rather put a new engine , but PD didn't have one. So with two cams on the shelf, in it went and out the door she did go. Cleaned her up inside of all the grey matter, made sure valves in the head worked nicely.
Cut to today, gentleman called and said it sounded like the crankshaft fell out of her. ~4 hours or so I'd say on the engine. Felt like a rod cap came loose. But what I found was the rod had broken at the wrist pin. One side of the pin had lots of wear. Loose in the piston. When you have lots of grey matter in an engine, do you guys go further? I assumed that I'd blast everything I could out of the inside and a new cam she'd be good to go. Nope.