My last 3 motorcycles were broken in the way you describe. Dynosaur oil for the first 1000 miles, (replaced after 600 miles;and again at 1000) then Mobil 1 thereafter. I always found lots of metal on the oil drain plug (magnetic)for the first 2 changes. Never had any problems with the bikes! Lenny Rosenbaum '87 5ksq '95 Yamaha 1100 Virago