HPDI/Plastic Part Question

The two plastic shrouds that are just above the lower unit, bolt to each other on the front of the midsection and clip into the side of midsection have rubber o-rings that wrap around the clips on the plastic piece. (Hope that makes sense)

I lost one of the plastic pieces and got a new one along with all new o-rings for the pieces on each motor since the old o-rings were broken.

Question is, what purpose do the o-rings serve?

[boats.net]

Probably just a damper.