Sounds like somebody is not thinking at the factory. Probably got a good deal on sealed rear bearings and stuck them in the engine, or were short sighted in trying to correct a nose bleed problem by installing a sealed bearing without a thought about the cam area. Of course, if the cam bearings are sealed that probably means they have a life time lubrication inside the seal and don't need to be lubed by the fuel. Don't know the answer but do know that it was a good catch by the end user. Not the first time such a problem has cropped up, I seem to recall the OS 70FL has a similar problem with a sealed main bearing.

Cheers,

Chip