Originally Posted by Bender
It's my understanding that the stock plastic sight glass will just get so brittle they eventually just let loose without over-pressurizing the crankcase. That is what I thought happened the first time.
It can for sure. If the second one went in that easily it was likely wrong, defective.
How hard was the third one?
As for the crank case vent, top left side of the motor, under the ABS unit forward of the Bowden Box. Sometimes they git pinched, or there is an obstruction in the air cleaner. Also drain your air cleaner to see if there is oil in it.