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Catalina/Capri 25/250 Sailor's Forums

General Sailing Forum

Milky oil in outboard lower unit

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dalelargent
Navigator

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USA
198 Posts

Initially Posted - 02/11/2013 : 17:45:20

Hi,

I did a search and didn't find what i was looking for, so decided to post.

I (finally - don't ask - it's been a long winter) got to winterizing my Honda 4-stroke outboard. The boat and motor are new to me as of last season.

All went well, until: The last thing I did was drain the oil in the lower unit. Milky. Honda manual says take it to a mechanic for inspection and repair. I am tight on cash, so hope to avoid that. But, I do get the importance of eliminating leaks in the lower unit.

The o-ring washers (plastic? nylon?) for the two drain screws look very worn. Not cracked, but certainly compressed. I suppose it COULD just be those - and replacing them would be cheap.

Do I "risk" trying just the washers, re-fill the oil and check it after a few uses in April? Or do I really need to take a deep breath and take it in for service? Is there some other part that commonly leaks and I could just replace that myself as well and improve my odds?

Thanks.

1989 c25 WK/TR #5838
1998 Catalina 36 mkii
1983 Vagabond 14

Edited by - on

Davy J
Master Marine Consultant

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USA
1511 Posts

Response Posted - 02/11/2013 : 18:11:40

I'm sure you will get some good info here. But, I use the iboat forums for specific engine questions. Some of the moderators are themselves mechanics. They have saved me a few trips to the shop for my powerboat as well as the sailboat.

http://forums.iboats.com/honda-tohatsu-nissan-outboards-29/

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bear
Admiral

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USA
909 Posts

Response Posted - 02/12/2013 : 09:16:00

OK, I too have a 4 stroke Honda, gray milky color of lower unit oil indicates water is mixing in. Don't believe the two seals on the drain/fill plugs would do that. Actually oil would leak from around the screw heads if motor was out of water. My Honda exhibits the same color oil. I just live with it and change oil every year. Oil coming out of lower end still has the texture of oil, just gray looking. Others will chime in here. But, there is a seal down around that output shaft. JMTCW

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DaveR
Master Marine Consultant

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USA
2015 Posts

Response Posted - 02/12/2013 : 09:47:38

From what I understand you should not have milky oil at all, at any time. If you do you've got a bad seal. That's probably not too expensive either.

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TakeFive
Master Marine Consultant

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2272 Posts

Response Posted - 02/12/2013 : 12:34:24

Milky oil means the seal is bad. Should be replaced ASAP. My assumption is that the risk of waiting depends on whether you're in salt water or not. Either case is risky, but getting salt water into your lower unit would be significantly more damaging.

FWIW, I did have milky oil in my Force 50 outboard when it was about 15 years old. I had a local mechanic rebuild the seal, and it's worked fine for the 6 years since. I have only used that outboard in fresh water on Lake Wallenpaupack.

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dmpilc
Master Marine Consultant

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USA
4593 Posts

Response Posted - 02/12/2013 : 13:11:43

Milky oil = water in the oil, most likely due to bad seals, and should be replaced. While you are at it, this is a good time to replace the impeller, too. If you want to avoid the shop and feel up to doing this yourself, download the lower unit diagrams and get familiar with the "landscape", make sure you have the proper tools or can borrow them, purchase the replacement seals, impeller, etc. and have a go at it.

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dalelargent
Navigator

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USA
198 Posts

Response Posted - 02/12/2013 : 13:39:17

This is great info! Thanks, all.

I am on fresh water, though plan on trips to San Juans :-)

Since it is a new motor to me, and now about 7 years old, AND a piece of safety equipment, I think i will take it to a shop. Seems worth it to know that motor is reliable. As cheap as I can be, I certainly can't afford a new lower unit or a damaged boat.

Thanks again.

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dalelargent
Navigator

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USA
198 Posts

Response Posted - 02/12/2013 : 15:41:23

Davy J,

How long would you run it before checking the oil condition if I followed that approach?

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Voyager
Master Marine Consultant

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USA
5378 Posts

Response Posted - 02/13/2013 : 19:25:05

Why bother doing lots of tests? Isn't your time worth something???

If you go to www.boats.net you will find exploded views of every outboard engine you can think of and you can see which O-rings and gaskets you need to buy. It could be, what, $80-100 in parts?

Think about how much the overhaul will cost. At least 2 hours labor at $80/hr plus $100 rebuild kit marked up by 50% plus the new oil and "shop supplies" (an old teeshirt for a rag) plus environmental disposal fees.

If it ain't $400 when he's done I'd be surprised. And "oh by the way the coil and plugs were shot and the starter rope was just about to go - good thing I spotted it" ka-ching, ka-ching.

If things really go bad, replacing the bottom unit could be over $900, so you don't want to go there.

It could be this seal or that O-ring but just do the whole job so you can rest easy. Use the diagram and take it step by step. Several of us have the maintenance manuals so you can always ask.

Good luck.

Edited by - Voyager on 02/13/2013 19:31:27

dlucier
Master Marine Consultant

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Virgin Islands (United Kingdom)
7583 Posts

Response Posted - 02/14/2013 : 06:58:51

If the lower unit isn't losing or dripping lube, water could be coming in from the top (water pump area) through the drive shaft or shift linkage seals.

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The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.