Thanks for the quick response.   Possibly.   The amount of aluminum in the oil seems like something is disintegrating badly esp only running it for a few minutes.   To waste more on parts and the time to pull it, put it back together I think it isn't worth it.  I need to cut and mulch leaves this week.   Con rod + two counterweight arms is about 150 shipped.  My time and if it doesn't work 

 !   Bought the Pony for 325 in March - cut the entire season.   Used to use a service which charged around 1850 so it paid for itself already.  Found a replacement which should be 31R907-0001-G1 for around 630 new in the box shipped free.   Know its a waste of money going this way but if I get a season or two it will pay for itself several times over.
I have to figure out the wiring on the new engine - old harness doesn't seem to match the new engine.   Should be able to work it out.