Could be the piston pin loose in the rod bushing. They make more noise when warm then cold.

 

I will be checking all the sizes when I pull it apart, I don't have the tapered end rods, they put the heavier (wider) ends on the forged crank witch is what I have and it's welded at the crank pin too. run-out at the shafts was .0003 pinion side and .0007 primary side. I know that has nothing to do with my noise, just thought I would put that out there. I really took my time and pre checked every component before I assembled it.

 

Bring her in. The clip that holds the piston to the rod could have come off which will then cause that pin to work it's way out and cause a real knocking and slapping sound. Not good if that's what happened. Good luck.