Hi again!  The mower seemed to be doing well when I started it today.  I put the new blades on and decided to try to mow.  I noticed a knocking noise developing.  I am having a hard time figuring out if it is coming from inside the engine or outside.  It is definitely around the engine though.  I have tried to look for anything that might be hitting or rubbing, but don't see anything obvious.  Everything feels like it is still tightly bolted on.  Here is a video of the noise...
https://youtu.be/w9LBIKQq0kE
I started to hear what almost sounds like something rattling around inside the engine, but only when I accelerate.  It is random and makes me envision something floating around in the engine in the oil.  I could be wrong, but that is what it sounds like.  I am concerned something else broke in there or I somehow missed a broken piece of the timing gear or camshaft.  Ugh.  I will have to try to get that noise on video tomorrow.
The grass has grown pretty tall since the mower has been down for a while.  I set the deck to 3" (what I normally use) but the mower struggled and vibrated pretty hard through thick patches.  I raised it up to 4" which made it a bit easier on the mower, but it still struggled through thick patches, just not as bad.  I doesn't seem to do as well as it did before hitting the stump and working on it.