I think after this weekends abuse with C27 I think its safe to say that there is no major flaw with the z400 bearing . The Dunbar trails have several areas where you can run flat out for several minutes at a time so if there was a flaw it would have grenaded then.
Here is a pic of a bearing with the low milage cage compared to a high mileage cage. The one on the bottom has .005" of the metal worn off from rubbing on the rod journal. The one on the top still has some copper coating on the low spots. I was able to reuse the rod that ran with the top cage .
I thought I would post another pic of a failed crank I pulled apart tonight.This one I did on a regular home use press no problem.Notice how the cage is welded to the pin.No evidence of heat other than the cage being stuck to pin.All the rollers were perfect.
Thanks to Brad Oakley who has sent me a new crank I will have the opportunity to pull apart a New crank.So far here are my measurements.Tommorrow I will split the crank and check out the guts.
Runout=.001 clutch side Runout=.0005 flywheel side Rod side clearance =.017-.018 Crank Width=2.473 No Sludge in crankpin at all Rod Big end ID=1.69425 Perfectly round
Its a shame to pull it apart since so far it is perfect but we can learn from this.Thanks Brad:clap: