Water in Lower Unit - Mariner 40HP

[Moody Blue]

Upon winterizing the motor this past fall I found the lower unit 1/2 full of water, 1/2 full of oil. When I started the season it had new oil put in it. Where do I look for the source of the water. (I know the lake .... ) I will be replacing the water pump impeller soon so if there is anything else I should do/check now will be the time. The pump seemed to be working fine but has been 2+ years since last replacement. Thanks for your time and thoughts.

 

[NathanY]

Re: Water in Lower Unit - Mariner 40HP

Probably the seals at the prop shaft. Take the prop off and see if there is any fishing line around the shaft. If not, take the lower unit off and take it to a mech and have it vac tested. That will give you a definitive answer.<br /><br />Another thought, it could also be the little gaskets that go behind the fill and vent screws...

 

[Moody Blue]

Re: Water in Lower Unit - Mariner 40HP

Interesting. I had checked the prop shaft and found nothing on it. Dry as well. No seepage at all. If water was getting in thru the prop shaft seal, would it also leak out there ? The fill and drain screws do look in rough shape. Think I'll change them out and install new gaskets. Is vacuum testing expensive ? Is it possible for water to get from the waterpump into the gear case ? Thanks again for the valuable info on this forum.