Put some screws in them, I would, if you ever would want to use them, then they wouldn't be full of dirt and debry.
“The modern astrophysical concept that ascribes the sun’s energy to thermonuclear reactions deep in the solar interior is contradicted by nearly every observable aspect of the sun.” —Ralph E. Juergens
Oh no, don't bother, not enough dirt comes in there to warrant any kind of sealing measure. My Neu is 2 years old now, and all I run on is gravel/dirt dusty conditions and it is very clean inside the motor. I only have the RCM Neu endbell cover.
“The modern astrophysical concept that ascribes the sun’s energy to thermonuclear reactions deep in the solar interior is contradicted by nearly every observable aspect of the sun.” —Ralph E. Juergens