Don't yell at me

[flyboyo2]

OK, I'm old so don't yell at me. My entire professional career entailed the scrupulous use of checklists so I made one for checking important  aspects of buying an old boat. Unfortunately I didn't make a check list to remember to bring my checklist on my purchase day. Consequently I failed to check the lower unit oil, which I did today, and found that there is oil in my lower units  water. I could turn both port screws with no effort and neither of them had a gasket. Could I be so lucky as to this is the problem?......naaaah.

[Capt. Bob]

Well, if you had a 91 Yamaha... maybe.

Water will enter past the fill screw if it's not tight and missing a gasket. I use fresh gaskets for each oil change and tighten the screws with a large common blade screwdriver that can be turned with a wrench.

Water usually enters via old seals in the lower unit but it never hurts to install the screw gaskets and tighten with a purpose (not gorilla tight that is). I get far less water since going to the new seals/wrench tightening method. I change my oil often because I still get trace amounts of water but nothing to get crazy about. I suggest you refill, add the new screw gaskets and tighten accordingly. After your first outing, check the screws and retighten as needed. After the second trip, check the oil for water.

Good luck.

[Capt. Bob]

Following up on my thoughts, how much water did you find?

Mostly water with a splash of oil?

White emulsion throughout?

Tan with streaks of white?

I ask because the above signs will indicate just how much water is getting into the lower unit (LO). Water (I believe) can also enter from above (the shaft seal below the water pump) so you need to look at that area also (while you're installing the new impeller, T stats and pressure relief valve ). This will give you a good indication where your problem (if any) lies. Another route would be to have a shop pressure test the LO and check for leaks.

If you go the gasket route first, you can pull the plug after the first outing and check the oil. It could give you a good idea what (if any) your next step will be. Changing the oil is relatively easy and inexpensive (comparatively) so as to give you a warm and fuzzy for the LO.

Good luck.

[flyboyo2]

Capt. Bob, thanks for the reply.  The fluid that drained, I'm hesitant to call it oil, was tan with streaks of white which seems to indicate a lot of water.  I'll try the easy fix first and refill with new washers and recheck.
I'm confident that the seals will have to be replaced, my question is are all the seals in the lower unit and is it a DYI job? The repair manual for the motor has not arrived yet, when it does I'll get a better handle on whether or not my limited mehanical skills are adeqate for the job.