Nissan NSF5A water in oil

Hello,

I took my outboard out of the shed to get her going a few weeks ago. I changed the oil and after replacing the spark plug got her going.


After dropping some crab traps, I left the boat on the shore for 2 about days, and when I went back she wouldn't start. I replaced the spark plug (again) and she started, but I noticed the oil was quite milky from water contamination.


What are the most probably routes of water ingress into the oil chamber? And are there any seal kits that I could buy to over-haul this thing?


...Any suggestions out there on which way I should proceed? I'm going to have a closer look this weekend.


I'm an amateur mechanic and I'm thinking this engine needs some love in terms of servicing. I just don't know what seals/gasket's I should be looking for.

Thanks in advance.

Could be rainwater or splashing after 2 days unattended. I would change the oil a couple more times and see if it's still getting contaminated. Then, if still getting water, the most likely seal is the head gasket.

Hi Paul,

Very nice to see you are still on these forums spreading your knowledge. Thanks very much for your input. I will change the oil again a few times.

If I am going to replace the head gasket...would you recommend installing any other new seals or gaskets while I'm at it?

Also...is it normal for spark-plugs to die really fast in a water contaminated chamber?

Thanks,
Jeff.

If the motor was ever overheated, the cylinder head gasket could leak. The gasket can be changed (with some dexterity) with the rest of the motor still assembled. There are 2 short and 2 long head bolts. You will need to pull the rocker cover, so you may need a new gasket for that. If you are worried about other gaskets, pull the power head off, and get a power head gasket set for about $55.00. Yes, if the plug is running in crud, it will fail quickly.

Hello All,

Thanks Paul for that answer! I ran up the engine after 2 oil changes and the oil got milky again pretty quick from just running in a test bin.

When you say that I'll need to pull the rocker cover...do you mean the head cover at the back? I'm guessing yes because that's where the bolt heads are.

I think slipping a new head gasket in look do-able. Replacing the other 20 parts in the power head gasket kit might be a little over my head (and maybe unnecessary?).
I think I'll just buy the kit and start with the head gasket (and rocker cover gasket if needed).

Looking at this picture...there are 2 "knocks" located at corners of the head (knock 8-12 in the parts manual). Are they there just for alignment? Looks like I may have to worry about them falling out when replacing the gaskets?


Cheers and Thanks again!
Jeff.

Yep, just alignment pins.

Hello,

I'm having difficulty removing the head-gasket. I've got the rocker cover off, and I've removed the 4 head bolts...but it seems like the exhaust port on the bottom of the head is attached to the body.

Is that what you meant but needing some dexterity to remove those bolts?

EDIT: Or is there a place you can direct me that has a bit more step-by-step instructions for breakdown? The parts manual is good, however I'm at a bit of a standstill with what to take off next.

Any help is appreciated.

Cheers,
Jeff.

There are a couple of bolts through through the oil pan that will allow the exhaust plate to disengage from the head. In most cases, I just remove the oil pan.

pvanv said:

There are a couple of bolts through through the oil pan that will allow the exhaust plate to disengage from the head. In most cases, I just remove the oil pan.

Click to expand...

OK, I can see that. But I can't seem to see how to remove the lower motor cover to gain access to said bolts. I'm obviously looking at this the wrong way.

Thanks Paul!

I usually pop off the power head.

Ok, Is it just these 6 bolts to take the power head off? If it is just those 6 bolts...I'm having a hard time lifting/prying it off? Does that sound about normal?

I may have to bite the bullet and purchase the service manual for $50 bucks when I buy the gasket kit? Arrggh...

Yep, just those 6 that connect the power head to the drive shaft housing. The base gasket may be pretty stuck after maybe 20 years.

Once again thank you!

A little love with a mallet and a few ratchet straps for support and I got her off! Let's hope all I need is a head gasket and there are no cracks.

Cheers!
J.