Originally Posted by
Glowgeek
I have seen rear factory bearings with shields as well. If I'm doing a bearing swap I remove the rear bearing shields, no need to restrict oil from migrating to the cam area in any way.
I also have seen several configurations of with and without, and partial shields. Never positive it was factory as I have never torn down a motor I bought new though.
Common sense dictates removal for obvious lubricant passage reasons.
Be interesting to know the answer to this long debated subject from Saito MFG.