Pontoon Boat & Deck Boat Forum

Is oil coming out of the "vent" screw normal? Also, what is the soft rubber piece hanging off the motor in picture 3? Thanks

Looks like the soft rubber piece is in picture #1. Sorry for the big pics, I thought downsizing them by 25% would be enough.

480 x 640 works good on the forum

With the screw removed or real loose oil should come out of the vent if the lower unit is full. If it's tight then you might be missing a gasket under the screw head. Not only will it loose oil but let water in. The piece your talking about is a hook up for a speedo meter. I resized your pictures.

I think Merc's use O rings to seal lower unit screws

Mercury uses fiber washers for their drain and vent screws.

If it's leaking, there could be a few causes:

Washer missing
Washer old (dried up and brittle)
Washer split/broken
Washer doubled up (previous service didn't remove old washer and put new one on top of it)

BoatCop wrote:Mercury uses fiber washers for their drain and vent screws.

If it's leaking, there could be a few causes:

Washer missing
Washer old (dried up and brittle)
Washer split/broken
Washer doubled up (previous service didn't remove old washer and put new one on top of it)

#2.... Yep!

You need to replace those every time you change your gear lube.