>>Right what caused this.  The engine builders could not
find any incidence of cooking the motor or other shoddy
servicing.  The damage has been caused to the bottom
end of the pistons.  Maybe those gudgeon pins walking
may have started it off.

Ray,
My guess would be that the dealer who serviced it cracked the pistons while
repairing the heads. Its not hard to crack the ends of the pistons,  for
example if you were to rotate the engine with the sleeves off but the pistons
still attached, they could easily get hung up on the side of the case and
crack.

Chris
86 Westy