1959 Johnson SH 10hp seal problem?

timcauliffe

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I recently purchased a 1959 Johnson Seahorse 10HP QD-20 motor. This was originally built as a double hose fuel system which I was able to successfully convert to a normal single hose with a new fuel pump. New prop, changed the gear oil and have been using it for weeks.

Earlier this week, I noticed some milky/grey oil (looks like water infiltrated gear oil) coming from the water intake port above the prop. My first inclination is bad seals. No shops around me seem to want to fix it as it's "too old for them", but I'm wondering if this is something I can do on my own?

Does it require removing the lower unit?
Is it something that can be done without needing to remove the lower unit?

Still runs perfect minus this leak.

Any help is appreciated!
 

Chinewalker

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Perfectly normal. You're seeing unburned fuel/oil mix that has collected in the various cavities inside the exhaust leg. You can mitigate it somewhat by using synthetic oils that burn "greener". Can also make sure the carb is in top condition and adjusted correctly (.ie as lean as it can go, minus 1/8 turn on the needles).
 

timcauliffe

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Perfectly normal. You're seeing unburned fuel/oil mix that has collected in the various cavities inside the exhaust leg. You can mitigate it somewhat by using synthetic oils that burn "greener". Can also make sure the carb is in top condition and adjusted correctly (.ie as lean as it can go, minus 1/8 turn on the needles).

Thanks!

Here are some pics of what I'm seeing:
(I can't upload images for some reason, but here's a link)

http://imgur.com/a/QO0XA
 

Chinewalker

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Hard to tell from the photo, but it does look like unburned fuel/oil. You can check your gear case oil if you like, looking for milkiness in the oil.
 

oldboat1

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Did you change out the impeller? Dropping the lower unit is not difficult (different exercise than changing seals).

Your motor has a thermostat up at the top. If it's missing or stuck open, the motor could be running cold -- less efficient and would likely increase the exhaust nasties in the leg. Running temp should be in the range of 120-140F or so (surface temp on the top of the head).
 

timcauliffe

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Did you change out the impeller? Dropping the lower unit is not difficult (different exercise than changing seals).

Your motor has a thermostat up at the top. If it's missing or stuck open, the motor could be running cold -- less efficient and would likely increase the exhaust nasties in the leg. Running temp should be in the range of 120-140F or so (surface temp on the top of the head).

If I have not changed out the impeller and unsure if previous owner did, should I do it any way?
 

timcauliffe

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Yup. Needs to be a priority. (DIY job).

New impeller purchased. Thanks for the tips.

Because I converted it to a single hose arrangement, is there any recommendation of a specific engine oil I should use when mixing with gas?
I am currently using Super Tech TC-W3, but I am wondering if there is something better?

Thanks again!
 

oldboat1

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should be fine. Synthetic oils may be a little cleaner, as Chinewalker suggests. Use an outboard oil rather than one intended for lawn tools. Other than that, I think it's a matter of preference. Run your '59 with a 24:1 mix.
 

timcauliffe

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should be fine. Synthetic oils may be a little cleaner, as Chinewalker suggests. Use an outboard oil rather than one intended for lawn tools. Other than that, I think it's a matter of preference. Run your '59 with a 24:1 mix.

Why 24:1 compared to the normal 50:1?
 

Chinewalker

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Your motor has a mixture of steel and bronze bearings. The steel bearings are likely fine with 50:1, but the bronze bearings are much happier with the fatter mix. In addition to lubrication, the oil volume will help seal things, particularly the center main.
 

timcauliffe

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Your motor has a mixture of steel and bronze bearings. The steel bearings are likely fine with 50:1, but the bronze bearings are much happier with the fatter mix. In addition to lubrication, the oil volume will help seal things, particularly the center main.
Thank you both and excuse my stupidity with this kind of stuff, but does this matter even though I converted it to single hose? With it now being single Jose, still stick with 24:1?
 
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