1963 johnson rds-25d 40hp - old gearcase oil color normal?

[grumpyguy]

So I am slowly bringing this motor back to life.

Compression checks out at 100 psi on each cylinder so good on that front. Decided to look at the oil in the gear case before I went ahead much further.

The motor has not been run for about 8 years now. Been through several freeze and thaws in Northern Ontario over those years obviously and was stored outside

So I removed the lower drain screw and drained the oil into a glass jar - it only had about 3/4 cup in it (about 6 ounces so 7 ounces short).

The color has me confused.

The oil is most certainly not milky white but is instead a color about the same as a strong cup of coffee with a teaspoon of whitener in it with a bit of green. No water came out when I removed the drain plug - I was sure to look for that. Also, there is no separation of oil and water in the jar as of yet (about 3 hours now). Viscosity is the same as new oil as well

Is this just old dirty gear oil? If water is in the gear case does it always turn a milky white? I've seen pictures of water intrusion a gear case on this site and Google and the old oil does not look like that.

Thanks in advance Gentlemen

 

[grumpyguy]

Looking at the undisturbed jar this morning this is no separation of oil and water. The is however light sediment on the bottom and no evidence of filings or metal bits. Bottom oil is darker than oil at the top of the jar and near the top its almost clear for 1/16" to an 1/8" of an inch.

 

[lindy46]

Probably just dirty old gear oil that's been in there for years. Could be some water in there if it is slightly milky, but I would think if there was water, it would have separated out after so many years, and it would have run out first. I'd just replace the oil, and run it for awhile and then check to see if water is getting in. Make sure to replace the washers/seals on the drain and vent bolts. Compression seems a little low for a 40hp. You may want to spray some penetrating oil in the cylinders and let them soak. Then re-check compression.

 

[grumpyguy]

No Title

Thanks for the response Lindy. I figure its just dirty as well but wanted the thoughts on members here with far more knowledge than I have.

I thought that 100 PSI was great. I have the full Johnson service manual and its silent on what the compression should be.

Here's a pic of the oil in a glass jar.

How would I clean the gear case out? Obviously I need to fill it but with what? Automotive tranny fluid?

 

[racerone]

Those gears and bearings are more rugged than modern motors.---------But it is elegantly easy to take the gearcase apart for inspection and cleaning.------Not sure why you simply would not do that !!

 

[grumpyguy]

Those gears and bearings are more rugged than modern motors.---------But it is elegantly easy to take the gearcase apart for inspection and cleaning.------Not sure why you simply would not do that !!

I would love to do that. Time is the issue here as is the season. I've got about two months of boating left before it gets too cold. Any thoughts on the old gear oil?

 

[GA_Boater]

I would start with fresh oil, grumpy. There is no telling how old the stuff was before it sat for eight years. The dye coloring may have just disappeared during that time. If it had water during the lay-up and the motor hasn't been running, it would separate and you could clearly see water at the bottom of the jar.

Refill the lower and run her a couple of times, then do another drain and see what it looks like. If you want to be absolutely positive, do what racerone suggested, open it up and look.

 

[grumpyguy]

I would start with fresh oil, grumpy. There is no telling how old the stuff was before it sat for eight years. The dye coloring may have just disappeared during that time. If it had water during the lay-up and the motor hasn't been running, it would separate and you could clearly see water at the bottom of the jar.

Refill the lower and run her a couple of times, then do another drain and see what it looks like. If you want to be absolutely positive, do what racerone suggested, open it up and look.

Those are my thoughts as well. Thanks everyone for the responses. Much appreciated and I wish I could return the favour in some way.

 

[Vic.S]

Thanks for the response Lindy. I figure its just dirty as well but wanted the thoughts on members here with far more knowledge than I have.

I thought that 100 PSI was great. I have the full Johnson service manual and its silent on what the compression should be.

Here's a pic of the oil in a glass jar.

How would I clean the gear case out? Obviously I need to fill it but with what? Automotive tranny fluid?

Any thoughts on the old gear oil?

I would say without doubt that oil contains water... It is definitely not "clear and bright" like new oil!.

I would fill the gearcase with some inexpensive automotive engine oil. Give it a run and then let it drain it thoroughly.
Refill it with new gear oil, fitting new seals to the drain and level screws, then check the condition from time to time.

All the while the oil remains "clear and bright" you know it is water free. If it goes cloudy, like the sample in your photo, it indicates that water is entering and that you will have to fit new seals.

 

[racerone]

Sorry, but you are taking longer to talk / discuss this issue than it would take to inspect the internal parts !!!

 

[grumpyguy]

Sorry, but you are taking longer to talk / discuss this issue than it would take to inspect the internal parts !!!

well I'm obviously not as skilled as you are racerone and trying to learn through these questions.

 

[oldboat1]

think I would first change out the gear oil, run it a bit and check the oil (likely drain again and refill) -- as suggested above. (Think I would just use OMC or Merc gear oil, and just get enough for a couple of refills.)

 

[racerone]

These gearcases are elegantly simple and no special tools / skills are required.-------So have a go at it !!!!!!!!